6th Period Honors Mid Term Exam 2011-2012

The correct answer is neutrons and protons. Neutrons and protons are subatomic particles that are located in the nucleus of an atom. Neutrons have no charge, while protons have a positive charge. Electrons, on the other hand, are located outside the nucleus in electron shells. Megatrons are not subatomic particles and do not exist.

Dalton's atomic model, also known as the billiard ball model, proposed that atoms were indivisible and indestructible particles. According to this model, atoms were the smallest unit of matter and did not contain any subatomic particles such as protons, neutrons, or electrons. Therefore, the given image, which depicts subatomic particles, is not an accurate depiction of Dalton's atomic model.

Atoms join to form bonds in order to achieve a full outer shell of valence electrons. The outermost shell of an atom, known as the valence shell, is responsible for the atom's chemical behavior. By forming bonds, atoms can share, gain, or lose electrons to complete their valence shell and achieve a more stable electron configuration. This allows them to attain a lower energy state, which is energetically favorable.

By using a crushed tablet in warm water, the surface area of the tablet is increased due to the smaller particle size. This allows for more effective collisions between the water molecules and the tablet, leading to a faster dissolution rate. Additionally, warm water has higher kinetic energy, which increases the speed of the molecules and therefore the rate of dissolution. Ultimately, this combination of a larger surface area and higher kinetic energy promotes a faster dissolution of the tablet, allowing the medicine to enter the body more quickly.

At a higher concentration, the reaction rate is faster because there are more reactant molecules available to collide and react with each other. This leads to the formation of a greater amount of products in a shorter period of time.

Using mathematics to describe a scientific event is considered a model because a model is a simplified representation of a real-world phenomenon. Mathematics provides a systematic and precise way to describe and analyze scientific events, allowing scientists to make predictions and understand the underlying principles. By using mathematical models, scientists can simplify complex systems, identify patterns, and test hypotheses. Therefore, it is true that using mathematics as a tool for describing scientific events is considered a model.

Weight is the correct answer because weight is the force with which gravity pulls on an object's mass. The weight of an object depends on its mass and the strength of the gravitational field it is in. Weight is measured in units of force, such as pounds or newtons.

The speed of light is represented in scientific notation as 3.0 X 10^8 m/s. In standard notation, this is simply written as 300,000,000 m/s.

A person with Apnea Sleep takes more total breaths per minute compared to a person with Normal Sleep. Apnea Sleep is a sleep disorder characterized by pauses in breathing or shallow breaths during sleep. These pauses can last for a few seconds to minutes and can occur multiple times throughout the night. As a result, the person with Apnea Sleep compensates for the lack of oxygen by taking more frequent and rapid breaths, leading to a higher total breaths per minute.

O2 is a molecule because it consists of two oxygen atoms bonded together. A molecule is a group of atoms held together by chemical bonds, and in this case, the two oxygen atoms are covalently bonded, forming the O2 molecule.

Aluminum (Al) is a pure substance. A pure substance is a type of matter that has a definite composition and cannot be separated into other substances by physical means. Aluminum is a chemical element with atomic number 13 and symbol Al. It consists of only one type of atom, making it a pure substance.

Noble gases have a full outer shell of electrons, making them stable and unreactive. This is because their outermost energy level is completely filled with electrons, so they do not need to gain or lose any electrons to achieve a stable electron configuration. Due to their high stability, noble gases rarely form chemical bonds with other elements and are therefore unreactive.

The given reaction is a synthesis reaction because it involves the combination of two reactants, nitrogen gas (N2) and hydrogen gas (H2), to form a single product, ammonia (NH3). In a synthesis reaction, two or more substances combine to form a more complex substance.

Atoms go through ionization in order to get a full outer shell of electrons. Ionization occurs when an atom gains or loses electrons, resulting in a charged particle called an ion. This process is necessary for atoms to achieve stability by obtaining a complete outer shell of electrons, which typically consists of eight electrons. Therefore, the statement is true.

When an atom gains an electron, it becomes negatively charged because the electron has a negative charge. This negatively charged atom is called an anion.

The scientific method is a systematic approach that scientists use to investigate and understand the natural world. It involves making observations, formulating hypotheses, conducting experiments, and analyzing data to draw conclusions. By following this method, scientists can organize their thoughts and approach problems or questions in a logical and structured manner. Therefore, the statement that the scientific method gives scientists a way to organize their thinking about a problem or question is true.

NaCl has a higher melting point compared to CO2. This is because NaCl is an ionic compound made up of sodium and chloride ions, which have strong electrostatic attractions between them. In contrast, CO2 is a covalent compound with weak intermolecular forces. The strong ionic bonds in NaCl require more energy to break, resulting in a higher melting point.

The symbol for the SI base unit for length is "m" which stands for meter. The meter is the standard unit of length in the International System of Units (SI) and is used to measure distances. It is defined as the distance traveled by light in a vacuum in 1/299,792,458 of a second. The meter is widely used in scientific and everyday measurements around the world.

The weight of the loaf of bread is given in grams. To convert grams to kilograms, we divide the weight in grams by 1000. Therefore, the correct answer is 1.362 kg.

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The statement suggests that the measurement of 6.13457902 cm is precise, meaning it has a high level of detail. However, it also states that the measurement may not be accurate, meaning it may not be close to the true value. This implies that although the measurement is precise, it may still have errors or deviations from the actual value, making the statement true.

The oxidation of a substance is a chemical property because it involves a chemical reaction where the substance combines with oxygen or loses electrons. This process leads to a change in the chemical composition of the substance, resulting in the formation of new compounds or the alteration of its properties. Physical properties, on the other hand, are characteristics that can be observed or measured without changing the composition of the substance. Since oxidation involves a chemical reaction and a change in composition, it is considered a chemical property.

Physical changes involve changing the states of matter (solid, liquid, gas). This can include processes like melting, freezing, boiling, or condensing. In these changes, the substances involved do not undergo a chemical reaction and their chemical composition remains the same. On the other hand, chemical changes involve the rearrangement of atoms and molecules, resulting in the formation of new substances with different chemical properties. Therefore, the correct answer is physical as it directly mentions the involvement of changing states of matter.

A polyatomic ion is a group of two or more atoms that are covalently bonded but act as a single charged particle. This means that the atoms within the ion are held together by covalent bonds, but as a whole, the ion carries a charge and behaves as a single unit. Polyatomic ions are often formed by the combination of nonmetal atoms, and they play a crucial role in many chemical reactions and compounds.

Scientific theories are constantly evolving and subject to change based on new discoveries and evidence. This is because the scientific method encourages the testing and modification of theories in light of new information. As new data is collected and analyzed, it may challenge or refine existing theories, leading to revisions or even complete changes in scientific understanding. Therefore, it is incorrect to say that scientific theories can never be changed when new discoveries are made.

The average atomic mass of an element is calculated by taking the weighted average of the masses of its isotopes, where the weights are the relative abundances of each isotope. In this case, the given answer of 20.187 is likely the result of calculating the average atomic mass of Neon using the masses of its three isotopes (20.1, 21.01, and 22.00) and their respective abundances.

It is colder than the other two because the reaction is happening at a slower rate

A bar graph would be the best kind of graph to show the density of different substances because it allows for easy comparison of the densities. Each substance can be represented by a separate bar, with the height of the bar indicating the density. This visual representation makes it easy to see the differences in density between the substances.

A measurement that is close to the true value indicates accuracy, while having several significant figures indicates precision. Therefore, a measurement that is both accurate and precise means that it is close to the true value and has a high level of detail and consistency.

Section 3 represents water in the liquid form only because it is the only section that does not have any other states of water mentioned. The question implies that there are multiple sections representing different states of water, and section 3 is the only one specifically mentioned to represent water in the liquid form.

The correct answer is exothermic. This is because the heaters in Army MRE's release heat energy when water is added, which in turn heats up the food. Exothermic reactions involve the release of heat energy into the surroundings.

In a chemical change, bonds between atoms are broken and new bonds are formed, resulting in the rearrangement of atoms to create new substances. This process involves a chemical reaction where the composition and properties of the substances involved change. On the other hand, in a physical change, there is no change in the composition or properties of the substances. While bonds may be broken in a physical change, they are not rearranged, and no new atoms are formed.

The correct answer is 7.89 X 10^11. In scientific notation, a number is written as a coefficient multiplied by 10 raised to a power. In this case, the coefficient is 7.89, and the power is 11. This means that the decimal point is moved 11 places to the right, resulting in a very large number.

Cooking an egg involves a chemical change. When an egg is heated, the proteins in the egg undergo denaturation, causing the egg to solidify. This change in the structure of the proteins is irreversible and leads to the formation of a new substance with different properties. Therefore, cooking an egg is an example of a chemical change rather than a physical change, which refers to changes in state or shape that can be reversed without altering the substance's chemical composition.

Sodium has higher metallic properties compared to chlorine. Metallic properties refer to the ability of an element to conduct heat and electricity, as well as its malleability and ductility. Sodium is a metal, while chlorine is a non-metal. Metals generally have higher metallic properties due to the presence of free electrons that can move freely and conduct electricity. Sodium is a good conductor of heat and electricity, and it is also malleable and ductile, which are characteristic of metals. Chlorine, on the other hand, is a poor conductor of heat and electricity and lacks the malleability and ductility of metals.

A scientific theory is an explanation that has been tested repeatedly with experiments. It is based on evidence and observations, and it provides a framework for understanding and predicting natural phenomena. Unlike a scientific law, which describes a specific relationship or pattern, a scientific theory is a broader explanation that encompasses multiple observations and experiments. It is supported by a large body of evidence and is subject to further testing and refinement. Therefore, a scientific theory is the correct answer in this case.

A scientific model is a representation of a real event or object that is usually too large or small to see. It is a simplified version that helps scientists understand and study complex phenomena. Scientific models can be physical, such as a scaled-down replica, or conceptual, such as a mathematical equation or computer simulation. They allow scientists to make predictions, test hypotheses, and gain insights into the workings of the natural world.

The measurement 40.00g is the most precise because it includes two decimal places, indicating a higher level of accuracy and precision compared to 40g and 40.0g, which have no decimal places or only one decimal place, respectively. The additional decimal places in 40.00g suggest that the measurement was taken with a more precise measuring instrument or technique.

The increase in ridership between 1998 and 2008 was 100,000.

Polyatomic ions can bond to each other because they are charged particles that contain multiple atoms. These ions have an overall charge and can form ionic bonds with other ions of opposite charge. When polyatomic ions come together, they can share or transfer electrons to achieve a stable configuration, resulting in the formation of a chemical bond. This allows polyatomic ions to combine and create compounds with different properties.

When multiplying measurements, the rule for significant figures states that the answer should have the same number of significant figures as the measurement with the fewest significant figures. In this case, the measurement with the fewest significant figures is 2.5 cm, which has 2 significant figures. Therefore, the answer should also have 2 significant figures.

The statement is false because particles in a solid are not completely still. Although they may vibrate in place, they still have some degree of motion. The particles in a liquid and gas, on the other hand, have more freedom of movement and are constantly in motion. Therefore, the correct answer is false.

The image contains only two distinct compounds.

Radon has a lower ionization energy compared to Neon. Ionization energy refers to the amount of energy required to remove an electron from an atom or ion. Radon, being a larger atom with more electron shielding, has a higher electron-electron repulsion, making it easier to remove an electron. Neon, on the other hand, is a smaller atom with less electron shielding, resulting in a higher ionization energy.

The alkali metals have one valence electron. This is because they belong to Group 1 of the periodic table, which means they have one electron in their outermost energy level. Having one valence electron makes them highly reactive and eager to lose that electron in chemical reactions.

The number .000670 has three significant figures. Significant figures are the digits in a number that carry meaning or contribute to its precision. In this case, the digits 6, 7, and 0 are all significant because they are not zero placeholders. The leading zeros before the decimal point are not significant as they only indicate the magnitude of the number. Therefore, the answer is 3 significant figures.

Chemical properties involve the formation of a new substance. When a chemical reaction occurs, the atoms rearrange themselves to form new chemical bonds, resulting in the creation of a different substance with different properties. This is in contrast to physical properties, which do not involve a change in the chemical composition of a substance. Therefore, the correct answer is "chemical" as chemical properties do involve the formation of a new substance.

100% pure orange juice is considered a mixture because it is made up of multiple components. Orange juice contains water, sugar, vitamins, minerals, and other compounds found in oranges. These components are not chemically bonded together, and they can be separated through physical means such as filtration or evaporation. Therefore, orange juice is classified as a mixture rather than a pure substance.

Photosynthesis is an example of a chemical change because it involves the conversion of carbon dioxide and water into glucose and oxygen, through the process of photosynthesis. This transformation requires the breaking and forming of chemical bonds, resulting in a new substance being formed.

This picture shows metallic bonding. Metallic bonding occurs between metal atoms, where the outer electrons are delocalized and form a "sea" of electrons that are free to move throughout the metal lattice. This type of bonding is responsible for the unique properties of metals, such as high electrical and thermal conductivity, malleability, and ductility.

The most likely reason for the increase in ridership and decrease in casualties in NYC from 1998-2008 is that NYC made bicycle lanes on most downtown roads. By providing designated lanes for cyclists, it encourages more people to ride bikes as they feel safer and more comfortable. This increase in ridership leads to more awareness and acceptance of cyclists on the roads, resulting in a decrease in casualties as drivers become more cautious and accustomed to sharing the road with cyclists.

Blood is a homogeneous mixture because it consists of various components, such as red and white blood cells, plasma, and platelets, that are uniformly distributed throughout the sample. These components cannot be easily separated or distinguished by the naked eye, making blood appear uniform in composition. Therefore, blood can be classified as a homogeneous mixture.

The given statement is false. Scientific theories do not become scientific laws when proven. A scientific theory is a well-substantiated explanation of some aspect of the natural world that is based on a body of evidence and has been repeatedly tested and confirmed through experimentation and observation. On the other hand, a scientific law is a statement that describes an observed phenomenon or pattern in nature without explaining why it occurs. Laws are often derived from theories but they are not the same thing.

The correct answer is elements and compounds. Elements are substances that cannot be broken down into simpler substances and are made up of only one type of atom. Compounds, on the other hand, are substances that are made up of two or more different types of atoms chemically combined together. Therefore, elements and compounds are the only two types of pure substances. Atoms and molecules are not types of pure substances, as atoms are the building blocks of elements and molecules are formed when atoms chemically combine. Heterogeneous and homogeneous refer to the types of mixtures, not pure substances.

The number 4,000,000 has 1 significant figure because all the zeros in this number are considered to be placeholders and do not contribute to the overall value or precision of the number. Therefore, only the digit 4 is significant.

The element belongs to the Halogens family. The Halogens family consists of elements in Group 17 of the periodic table, including fluorine, chlorine, bromine, iodine, and astatine. These elements are highly reactive nonmetals and have seven valence electrons, making them eager to gain one electron to achieve a stable electron configuration. They are known for their strong oxidizing properties and ability to form salts with metals.

you must DECREASE the pressure in order to increase the reaction rate. This is because decreasing the pressure will allow for the particles to move faster and contact each other more often

Not all molecules are considered "compounds". A compound is a type of molecule that is made up of two or more different elements chemically bonded together. However, there are also molecules that consist of only one type of element, such as oxygen gas (O2) or nitrogen gas (N2), which are not considered compounds. Therefore, the statement that all molecules are considered "compounds" is false.

The number 4.065 has four significant figures because all non-zero digits are considered significant and the zero between the 4 and 6 is also significant.

This reaction is a single replacement reaction because a single element (Li) is replacing another element (H) in the compound (H2O).

The given number, .0009234, can be expressed in scientific notation as 9.2 x 10^-4. In scientific notation, the number is written in the form of a decimal number between 1 and 10 multiplied by a power of 10. In this case, the decimal number is 9.2, and the power of 10 is -4, indicating that the decimal point is moved 4 places to the left.

O2 is not a compound because it consists of only one element, oxygen. Compounds are formed when two or more different elements chemically combine. Since O2 is made up of only oxygen atoms, it is considered a molecule rather than a compound.

Chemists need to work with balanced equations because of the law of conservation of mass. This law states that matter cannot be created or destroyed in a chemical reaction, only rearranged. Balanced equations ensure that the number of atoms of each element is equal on both sides of the equation, representing the conservation of mass. By working with balanced equations, chemists can accurately calculate the amounts of reactants needed and products formed in a chemical reaction.

The number .0034 is written in scientific notation as 3.4 X 10^-3. In scientific notation, the number is expressed as a decimal between 1 and 10 multiplied by a power of 10. In this case, the decimal 3.4 is multiplied by 10 raised to the power of -3, which represents three places to the right of the decimal point.

According to Bohr's model of the atom, the 3rd energy level can hold up to 18 electrons, not 8. This is because each energy level has a maximum capacity of 2n^2 electrons, where n is the principal quantum number. For the 3rd energy level (n=3), the maximum number of electrons is 2(3)^2 = 18. Therefore, the statement that the 3rd energy level can only hold up to 8 electrons is false.

Ionic bonds are formed between a metal and a non-metal, resulting in the transfer of electrons from the metal to the non-metal. This creates ions with opposite charges, which are attracted to each other and form a crystal lattice structure. When dissolved in water, these ions dissociate and become free to move, allowing the solution to conduct electricity. Therefore, ionic bonds will conduct electricity when dissolved in water.

John Dalton's atomic theory from the early 1600s did not include the concept that atoms have subatomic particles. According to Dalton's theory, atoms were considered indivisible and indestructible particles. It was later discovered that atoms are composed of subatomic particles such as protons, neutrons, and electrons. This discovery led to the development of the modern atomic theory.

Technology can be defined as the practical application of scientific knowledge. It involves using scientific principles and theories to create tools, machines, systems, and processes that solve problems, improve efficiency, and enhance human life. Technology takes the theoretical concepts and ideas from science and applies them in real-world situations to create innovative solutions and advancements. It is the bridge between scientific knowledge and its practical implementation, making science usable and accessible in various industries and fields.

Dry ice going from a solid directly to a gas is an example of sublimation. Sublimation is the process in which a substance transitions directly from a solid to a gas without going through the liquid state. In the case of dry ice, which is solid carbon dioxide, it undergoes sublimation when exposed to room temperature, causing it to change into carbon dioxide gas.

Scientists often use computer models to study complicated events or large amounts of data in order to make predictions. Computer models allow scientists to simulate and analyze complex systems or phenomena that may be difficult or impossible to observe directly. By inputting data and variables into the computer model, scientists can manipulate and analyze the information to understand patterns, relationships, and potential outcomes. Computer models can provide valuable insights and predictions that help scientists make informed decisions and further their understanding of the subject matter.

When adding or subtracting numbers, the result should be rounded to the least number of decimal places in the original numbers. In this case, 2.02 g has three decimal places and 1.6 g has one decimal place. Therefore, the answer should be rounded to one decimal place, which is 3.6 g.

Baking soda (NaHCO3) is a pure substance because it is a compound that is made up of a fixed ratio of sodium (Na), hydrogen (H), carbon (C), and oxygen (O) atoms. It has a definite chemical composition and cannot be separated into different components by physical means. Therefore, it is considered a pure substance.

The bottom left corner of the periodic table refers to the elements in the s-block and the f-block. These elements have larger atomic radii compared to the elements in other sections of the periodic table. This is because the electrons in these elements are found in higher energy levels and are further away from the nucleus, resulting in a larger atomic radius.

Radon is a chemical element with atomic number 86. The atomic number represents the number of protons in an atom, which is also equal to the number of electrons in a neutral atom. Therefore, there are 86 electrons in one element of Radon.

A molecule is a group of atoms bonded together, while a compound is a molecule that contains atoms of different elements. Therefore, it is possible to have a molecule that consists of only one type of atom, such as oxygen gas (O2), which is not a compound.

Accuracy is the extent to which a measurement is close to the true or target value. It indicates how well the measurement represents the actual value being measured. A measurement can be precise but not accurate if it consistently gives the same result but is not close to the true value. Therefore, accuracy is a crucial factor in determining the reliability and validity of a measurement.

Deposition is the process in which a substance transitions directly from a gas to a solid state without passing through the liquid phase. This occurs when the temperature of the gas is lowered to a point where the particles lose enough energy to come together and form a solid. The solid particles are deposited onto a surface, resulting in the formation of a solid.

When a substance goes from a solid to a liquid, it is called melting. This process occurs when the temperature of the substance increases and the intermolecular forces holding the particles in the solid lattice weaken, allowing them to move more freely and form a liquid. Deposition refers to the process where a gas directly transforms into a solid without passing through the liquid phase. Sublimation is the process where a solid directly transforms into a gas without passing through the liquid phase. Freezing, on the other hand, is the transition from a liquid to a solid state.

This bond is covalent because it involves the sharing of electrons between atoms. In a covalent bond, atoms share electrons in order to achieve a stable electron configuration. This type of bond typically occurs between nonmetal atoms.

A covalent bond is formed when two atoms share electrons. In this type of bond, the atoms involved have similar electronegativities, meaning they have similar tendencies to attract electrons. As a result, the shared electrons are not completely transferred from one atom to another, but rather are shared between the atoms. This sharing of electrons creates a strong bond between the atoms, allowing them to form stable molecules.

The explanation for the correct answer is that natural science is concerned with the study of the natural world and includes disciplines such as physics, chemistry, biology, and geology. On the other hand, social science is concerned with the study of human society and social relationships, including disciplines such as sociology, psychology, anthropology, and economics. Therefore, the statement that the two main branches of science are natural and social science is true.

The explanation for the given correct answer is that the Periodic Law indeed states that when atoms are arranged by the number of protons, they exhibit a pattern of chemical and physical properties. This means that elements with similar numbers of protons will have similar properties, while elements with different numbers of protons will have different properties. This pattern is the basis for the organization of the periodic table, where elements are arranged in order of increasing atomic number. Therefore, the statement "The Periodic Law states that when atoms are arranged by the number of protons they show a pattern of chemical and physical properties" is true.

When multiple pure substances are added together, it is called a mixture. A mixture is a combination of two or more substances that are not chemically bonded together. In a mixture, the substances retain their individual properties and can be separated by physical means, such as filtration or distillation. Unlike compounds, which are formed by the chemical combination of elements, a mixture does not have a fixed composition and can have varying proportions of its components.

The number 7.89 x 10^10 has three significant figures because the digits 7, 8, and 9 are all non-zero and therefore significant. The exponent 10^10 does not affect the number of significant figures.

The answer is surface area because a substance broken down into smaller chips would have a greater surface area making the reaction happen faster

The image shows a structure with 6 distinct molecules.

The correct answer is heterogeneous because an oil and water mixture consists of two immiscible substances that do not blend uniformly. Oil and water do not mix due to differences in their polarities and densities, resulting in visible separation between the two substances. Therefore, the mixture is considered heterogeneous.

Alkali metals, such as sodium and potassium, have a single valence electron in their outermost energy level. They have a strong tendency to lose this electron and form a positive ion. On the other hand, non-metals, such as chlorine and oxygen, have a strong tendency to gain electrons and form negative ions. When an alkali metal reacts with a non-metal, such as in the case of sodium reacting with chlorine to form sodium chloride, the alkali metal loses its valence electron and the non-metal gains it. This transfer of electrons results in the formation of an ionic bond, where the positive and negative ions are attracted to each other due to their opposite charges. Therefore, alkali metals are likely to form ionic bonds.

The correct electron configuration for Bromine is [Ar] 4s23d104p5. This means that Bromine has a total of 35 electrons. The electron configuration indicates the distribution of these electrons in different energy levels and orbitals. The [Ar] represents the electron configuration of the noble gas Argon, which has 18 electrons. The 4s23d104p5 indicates that there are 2 electrons in the 4s orbital, 10 electrons in the 3d orbital, and 5 electrons in the 4p orbital.

Halogens are a family of elements that often form anions and are highly reactive with alkali metals to achieve a full outer shell. This reactivity is due to their high electronegativity and tendency to gain one electron to achieve a stable electron configuration. The halogens include elements such as fluorine, chlorine, bromine, and iodine, which readily react with alkali metals like sodium and potassium to form ionic compounds. This reaction allows the halogens to gain an electron and the alkali metals to lose an electron, resulting in both elements achieving a stable electronic configuration.

A scientific law is a statement that describes a natural event or phenomenon based on repeated observations and experiments. It provides a concise and reliable description of how a particular aspect of the natural world works. However, it does not provide an explanation for why the event occurs or the underlying mechanisms involved. Laws are often used to predict and understand the behavior of natural phenomena, but they do not delve into the deeper causes or reasons behind them.

Based on the information provided, at the 20 second mark of the experiment, a magical reaction occurs. The term "endothermic" refers to a reaction that absorbs heat from its surroundings, causing a decrease in temperature. Therefore, it is likely that the magical reaction described in the question is endothermic, as it is absorbing heat from its surroundings.

A hypothesis is a possible answer or explanation to a scientific problem. It is a proposed explanation based on observations and previous knowledge that can be tested through experimentation and further investigation. A hypothesis serves as a starting point for scientific research and provides a framework for designing experiments and collecting data to either support or refute the proposed explanation.

The number of protons in the nucleus determines the atomic number of an element, which is unique to each element. This number defines the identity of the element and differentiates it from other elements. The number of protons also determines the number of electrons in a neutral atom, as atoms are electrically neutral and have an equal number of protons and electrons. Therefore, the number of protons in the nucleus is what makes the atoms of one element different from the atoms of another element.

The correct answer is pure substance because capsaicin, C18H27NO3, is a specific compound with a fixed chemical composition. It is not a mixture of different substances or elements.

Scientists use models to represent real situations and to make predictions. Models are simplified representations of complex systems or phenomena that help scientists understand and analyze them. By inputting data and variables into these models, scientists can simulate and predict how the real situation will behave under different conditions. These predictions can then be tested and validated through experiments or observations, allowing scientists to gain insights and make informed decisions based on the model's outputs.

An isotope is when an atom has the same number of protons but a different number of neutrons, not electrons. Isotopes have the same atomic number (number of protons) but different atomic mass (number of neutrons). Therefore, the correct answer is False.

Radon is a chemical element with atomic number 86. The atomic number represents the number of protons in an atom's nucleus. Since the atomic number of Radon is 86, it means that there are 86 protons in one element of Radon. Neutrons are particles found in the nucleus of an atom, and their number can vary. To find the number of neutrons, we subtract the atomic number from the atomic mass. The atomic mass of Radon is 222, so subtracting 86 from 222 gives us 136 neutrons. Therefore, there are 136 neutrons in one element of Radon.

An atom of Helium has a full outer shell of 2 electrons, not 8. The first shell can hold a maximum of 2 electrons, and since Helium has only 2 electrons, its outer shell is considered full.

Alkali metals are highly reactive with water because they have only 1 valence electron. This electron is easily lost, making them highly reactive and prone to forming positive ions. The alkali metals include elements such as lithium, sodium, and potassium, which are known for their vigorous reactions with water, releasing hydrogen gas and forming hydroxides. They are located in the first column of the periodic table and are known for their low melting and boiling points, as well as their softness.

During sublimation, a substance transitions from a solid directly to a gas without going through the liquid phase. This process requires energy input to overcome the intermolecular forces holding the particles together in the solid state. Therefore, energy is gained during sublimation.

An ionic bond is a bond formed between oppositely charged ions. In this type of bond, one atom donates electrons to another atom, resulting in the formation of positively charged cations and negatively charged anions. These ions are then attracted to each other due to their opposite charges, creating a strong bond. Ionic bonds typically occur between a metal and a non-metal, where the metal atom loses electrons to form a positive ion, and the non-metal atom gains those electrons to form a negative ion. This mutual attraction between the ions forms a stable bond.

A metallic bond is formed when there is a strong attraction between the positively charged nuclei of metal atoms and the negatively charged "sea" of electrons that are delocalized and free to move throughout the metal structure. This type of bond allows for the high electrical and thermal conductivity observed in metals, as well as their malleability and ductility. In a metallic bond, the electrons are shared among all the atoms in the metal lattice, creating a strong and cohesive structure. This is different from covalent bonds, where electrons are shared between two atoms, and ionic bonds, where electrons are transferred from one atom to another.