Clintondale Physical Science Exam Review

Social science is not a branch of natural science because it focuses on the study of human society and social relationships. It involves disciplines such as sociology, psychology, anthropology, economics, and political science. Unlike natural sciences, which aim to understand the natural world and its phenomena, social sciences examine human behavior, cultures, societies, and institutions. While both natural and social sciences contribute to our understanding of the world, they differ in their subject matter and research methods.

In the scientific method, making observations is the step in which information is obtained through the senses. This involves using our senses to gather data and information about a specific phenomenon or experiment. By carefully observing and gathering data, scientists can collect information that will later be used to draw conclusions, analyze data, and revise hypotheses. Making observations is an essential step in the scientific method as it provides the foundation for further analysis and experimentation.

One centimeter is equal to 10 millimeters. This is because there are 10 millimeters in one centimeter.

The principle of conservation of energy states that energy cannot be created or destroyed, but it can only be transferred or transformed from one form to another. This means that the total amount of energy in a system remains constant before and after a chemical reaction. Therefore, the correct answer is "conserved".

The prefix "di-" in the name carbon dioxide indicates that a molecule of carbon dioxide contains two oxygen atoms.

A model is a physical or mental representation of an object or an event. It can be a simplified version or a simulation that helps us understand and explain complex phenomena. Models are used in various fields such as science, engineering, and mathematics to study and predict real-world situations. They provide a visual or conceptual framework that aids in conceptualizing and analyzing the behavior and characteristics of the object or event being represented.

The pressure of an enclosed gas is affected by temperature, volume, and the number of particles. When the temperature of a gas increases, the average kinetic energy of the gas particles also increases, leading to more frequent and forceful collisions with the walls of the container, thus increasing the pressure. Similarly, when the volume of the container decreases, the gas particles have less space to move, resulting in more frequent collisions and a higher pressure. Additionally, increasing the number of gas particles in the container increases the frequency of collisions, leading to an increase in pressure. Therefore, all of these factors affect the pressure of an enclosed gas.

The structural formula with symbols connected by a long dash indicates a covalent bond. In covalent bonds, atoms share electrons to achieve a stable electron configuration. This type of bond is common in nonmetals and results in the formation of molecules. Ionic bonds involve the transfer of electrons between atoms, while metallic bonds involve a sea of delocalized electrons surrounding positive metal ions. The term "unstable" does not accurately describe the nature of the chemical bonds based on the given information.

During a redox reaction, electrons are both gained and lost. This is because redox reactions involve the transfer of electrons from one species to another. The species that gains electrons is said to be reduced, while the species that loses electrons is said to be oxidized. Therefore, the overall reaction involves both the gain and loss of electrons.

Filtration is a process used to separate mixtures by passing them through a filter medium that allows only smaller particles to pass through while retaining larger particles. This method is effective in separating mixtures based on the size of their particles. By using a filter with specific pore sizes, particles that are larger than the pores will be trapped, while smaller particles will pass through. Therefore, filtration can be used to separate mixtures based on the size of their particles.

In Neils Bohr's model of the atom, electrons move like planets orbiting the sun. This means that the electrons move in fixed, circular orbits around the nucleus of the atom, similar to how planets move in fixed orbits around the sun. This model suggests that electrons have specific energy levels and can only exist in these discrete orbits, rather than moving freely throughout the atom. This concept helps explain the stability of atoms and the emission and absorption of energy by electrons.

Compounds are considered pure substances because they are made up of a fixed ratio of two or more elements chemically combined together. Unlike mixtures, compounds cannot be separated by physical means and have distinct properties. Therefore, compounds are the correct answer as pure substances.

In an atomic model that includes a nucleus, positive charge is concentrated in the center of the atom. The nucleus is made up of positively charged protons and neutral particles called neutrons. The protons carry positive charge and are tightly packed in the nucleus, while the electrons, which carry negative charge, are located in the space outside the nucleus. This concentration of positive charge in the center of the atom creates an overall neutral charge, as the number of protons is equal to the number of electrons.

The tendency of an element to react chemically is closely related to the number of valence electrons in atoms of the element. Valence electrons are the outermost electrons in an atom and they are involved in chemical reactions. The number of valence electrons determines the element's ability to form bonds with other atoms and participate in chemical reactions. Elements with a full outermost electron shell tend to be stable and have a lower tendency to react, while elements with incomplete outermost electron shells are more reactive and likely to form bonds with other atoms to achieve stability.

The molar mass of Cr is 52 g/mol. To find the number of moles, divide the given mass (156 g) by the molar mass of Cr. 156 g / 52 g/mol = 3.0 mol.

In a metal lattice, the atoms are arranged in a regular pattern, forming a crystal structure. The outermost electrons of the metal atoms are not tightly bound to their respective atoms and are free to move throughout the lattice. This mobility of electrons allows metals to conduct electricity and heat effectively. Therefore, the statement "Electrons in a metal lattice are free to move" is true.

In a compound, chemical energy is contained in the bonds. Bonds are formed when atoms share or transfer electrons, and the energy required to form these bonds is stored within them. Breaking these bonds releases the stored energy, which can be used for various chemical reactions or processes. Therefore, the bonds in a compound hold the chemical energy that can be released or utilized.

Charles' law states that the volume of a gas is directly proportional to its temperature in kelvins if the pressure and the number of particles are constant. This means that as the temperature of a gas increases, its volume will also increase proportionally, and vice versa. This law is named after Jacques Charles, a French physicist, who first discovered this relationship between temperature and volume in the late 18th century.

Vaporization is an endothermic change because it requires energy input to break the intermolecular forces between liquid particles and convert them into gas particles. This energy is absorbed from the surroundings, causing a decrease in temperature. Condensation, deposition, and freezing, on the other hand, are exothermic changes as they release energy to the surroundings, resulting in an increase in temperature.

Rutherford provided evidence for the existence of a nucleus in an atom through his famous gold foil experiment. In this experiment, Rutherford directed a beam of alpha particles at a thin sheet of gold foil. He expected the alpha particles to pass through the foil with minimal deflection. However, some of the particles were deflected at large angles, and a few even bounced back. This led Rutherford to conclude that the atom must contain a small, dense, and positively charged nucleus at its center, surrounded by mostly empty space where the electrons orbit.

When an electron moves to a higher energy level, it means that it has absorbed energy from an external source. This can happen when the electron absorbs a photon of light or when it interacts with another particle. As a result, the electron gains energy and moves to a higher energy level. This process does not make the atom more stable, but rather indicates that the electron is in an excited state.

In an electron dot diagram, the symbol for an element is used to represent the nucleus. This is because the electron dot diagram is a simplified representation that focuses on the valence electrons, which are the electrons in the outermost energy level of an atom. The symbol of the element represents the nucleus, which contains the protons and neutrons of the atom. The valence electrons are then represented by dots or crosses around the symbol, indicating their presence in the outermost energy level.

One mole of any substance contains Avogadro's number of particles, which is approximately 6.02 x 10^23. Therefore, 2 moles of chromium would contain 2 times Avogadro's number of atoms, which is 2 x 6.02 x 10^23 = 1.20 x 10^24 atoms.

A change in shape is not a clue that a chemical change has occurred because a change in shape only indicates a physical change, not a chemical change. Chemical changes involve the rearrangement of atoms and the formation of new substances with different chemical properties. In contrast, changes in shape usually involve a change in the arrangement or position of molecules or particles, but the chemical composition remains the same. Therefore, a change in shape is not a reliable clue to determine if a chemical change has occurred.

According to John Dalton's observations, the ratio of the masses of elements in a compound is always the same. This means that when elements combine to form a compound, the proportion of their masses remains constant. This observation led to the development of the law of definite proportions, which states that a compound always contains the same elements in the same proportion by mass. This is a fundamental principle in chemistry and helps in understanding the composition of compounds and their reactions.

Bronze is an alloy that primarily consists of copper and tin. It is commonly used in various applications due to its durability, strength, and resistance to corrosion. Bronze has been used for centuries in the production of statues, coins, musical instruments, and decorative items. It is known for its distinctive reddish-brown color and is a popular choice for casting and sculpting due to its malleability. Therefore, bronze is the correct answer as it is the alloy that contains mainly copper and tin.

The given chemical reaction is classified as exothermic because it releases energy in the form of kJ.

Reactants are the substances that are present before a chemical reaction takes place. They are the starting materials that undergo a chemical change to form new substances called products. Reactants are consumed during the reaction and are transformed into different compounds or elements. Coefficients are used to balance the chemical equation, while elements refer to the basic building blocks of matter.

The number 0.00025 can be written in scientific notation as 2.5 x 10^-4. In scientific notation, the number is expressed as a decimal between 1 and 10 (in this case, 2.5) multiplied by a power of 10 (in this case, -4). This indicates that the decimal point is moved 4 places to the left, resulting in a smaller number.

The correct answer is "slope." In a linear relationship, the slope represents the ratio of the change in the dependent variable to the change in the independent variable. It indicates how the two variables are related and whether they are directly proportional (positive slope) or inversely proportional (negative slope). Therefore, the ratio of the manipulated variable and the responding variable is constant in a relationship defined by the slope.

A mixture can be classified as a solution, suspension, or colloid based on the size of its largest particles. A solution is a homogeneous mixture where the particles are uniformly distributed and cannot be seen with the naked eye. A suspension is a heterogeneous mixture where the particles are larger and can be seen and easily separated by settling or filtration. A colloid is also a heterogeneous mixture, but the particles are smaller and do not settle, giving it a cloudy or milky appearance. Therefore, the size of the largest particles in a mixture determines its classification.

When the temperature and volume of a gas remain constant, according to the ideal gas law, the pressure of the gas is directly proportional to the number of particles of gas. Therefore, if the number of particles of gas is increased, the gas pressure will also increase. This is because an increase in the number of gas particles leads to more frequent collisions with the container walls, resulting in a higher pressure.

In the compound MgCl2, the subscript 2 indicates that there are two chloride ions for each magnesium ion. This means that for every one magnesium ion, there are two chloride ions present in the compound. The subscript 2 represents the ratio of the ions in the compound, indicating that the compound is formed by the combination of one magnesium ion and two chloride ions.

Ionic compounds typically have a tendency to shatter when struck. This is because ionic compounds are made up of positive and negative ions held together by strong electrostatic forces. When a force is applied to an ionic compound, the ions are not able to move past each other easily, causing the compound to break apart into smaller pieces. This property is characteristic of the rigid and brittle nature of ionic compounds.

A synthesis reaction is a type of chemical reaction where two or more reactants combine to form a single product. The general formula for a synthesis reaction is A + B --> C, indicating that two reactants (A and B) combine to form a single product (C). However, it is not always true that there is only one reactant in a synthesis reaction. In some cases, there may be more than one reactant involved, resulting in the formation of a single product. Therefore, the statement "There is only one reactant" is NOT always true about a synthesis reaction.

A compound is formed when two or more different elements are chemically bonded together in a fixed proportion. In this case, the material contains three elements joined in a fixed proportion, indicating that it is a compound. A mixture, on the other hand, is a combination of substances that are not chemically bonded and can be separated by physical means. A solution is a type of mixture where one substance (solvent) is evenly distributed in another substance (solute). An atom is the basic unit of matter and cannot be further broken down into simpler substances.

During a phase change, such as from solid to liquid or from liquid to gas, the temperature of a substance remains constant. This is because the energy being absorbed or released is used to break or form intermolecular bonds rather than increase or decrease the kinetic energy of the particles. Once all the substance has completed the phase change, the temperature will begin to increase or decrease again.

In a periodic table, a set of properties repeats from row to row. This means that elements within the same row or period share similar chemical properties and exhibit a gradual change in properties as you move across the table from left to right. The repetition of properties is due to the gradual increase in the number of protons and electrons as you move across a row, which affects the arrangement of electrons in the atom and thus its chemical behavior.

The atomic mass of an element is determined by taking a weighted average of the masses of the isotopes present in nature. Isotopes are atoms of the same element that have different numbers of neutrons. Since different isotopes of an element have different masses, the atomic mass is calculated by considering the abundance of each isotope in nature. The more abundant isotopes contribute more to the overall atomic mass, while the less abundant isotopes have a smaller impact. By taking a weighted average, the atomic mass accurately represents the average mass of all the isotopes of an element.

Helium and neon are the gases that emit colors when an electric current is applied. This is because they have unique electron configurations that allow them to absorb and release energy in the form of light. When an electric current passes through these gases, the electrons in their outer energy levels become excited and jump to higher energy levels. As the electrons return to their original energy levels, they release energy in the form of light, creating the characteristic colors associated with helium and neon.

The atomic mass of an element is defined as the average mass of all the isotopes of that element, taking into account the abundance of each isotope. The atomic mass unit (amu) is a unit of measurement used to express atomic and molecular weights. Therefore, it makes sense that the one-twelfth the mass of a carbon-12 atom is used to define the atomic mass unit (amu), as it provides a standard reference point for measuring the masses of other atoms. The atomic number represents the number of protons in an atom's nucleus, while the mass number represents the total number of protons and neutrons. Neither of these definitions relates to the given statement.

Cs (cesium) is the most reactive Group 1A element because it has the largest atomic radius. As you move down the periodic table within a group, the atomic radius increases. This means that the outermost electron in Cs is further away from the nucleus compared to the other elements in Group 1A. As a result, Cs's outermost electron is less strongly attracted to the nucleus, making it easier to lose that electron and form a positive ion. Therefore, Cs exhibits the highest reactivity among the given Group 1A elements.

Water has a higher boiling point than expected because of the strong attractions between polar water molecules. These attractions, known as hydrogen bonds, occur due to the partial positive charge on the hydrogen atoms and the partial negative charge on the oxygen atom in water molecules. These hydrogen bonds require more energy to break, leading to a higher boiling point for water compared to other substances.

The column on the far left of the periodic table contains the most reactive metals. This is because as you move from left to right across a period, the atomic size decreases and the number of valence electrons increases. The most reactive metals are found in Group 1, also known as the alkali metals, which have one valence electron and readily lose it to form a positive ion. These metals are highly reactive and easily react with water or oxygen.

The correct answer is "its molecule has a bent shape". The water molecule has a bent shape due to the presence of two lone pairs of electrons on the oxygen atom. This bent shape causes an asymmetrical distribution of charge within the molecule, resulting in a polar molecule. The oxygen atom is more electronegative than the hydrogen atoms, causing the oxygen to have a partial negative charge and the hydrogen atoms to have partial positive charges. This polarity allows water molecules to form hydrogen bonds with each other, giving rise to the unique properties of water such as high boiling point, surface tension, and solvent capabilities.

Carbon is found in most of the compounds in the human body except for water. Carbon is a key element in organic compounds, including carbohydrates, lipids, proteins, and nucleic acids, which are essential for life. It forms the backbone of these molecules and participates in various chemical reactions. While iodine, potassium, and iron are also important elements in the body, they are not found in as many compounds as carbon.

Silicon is a better conductor of an electric current than sulfur is. This is because silicon is a semiconductor, meaning it can conduct electricity under certain conditions. While it is not as good of a conductor as metals like silver, it still has some conductivity. On the other hand, sulfur is a nonmetal and is a poor conductor of electricity. Therefore, silicon is a better conductor of an electric current than sulfur.

The atom in the ground state has less energy and is less stable than the atom in an excited state because in the ground state, the electrons occupy the lowest energy levels. When an atom is in an excited state, one or more electrons have absorbed energy and moved to higher energy levels. This results in the atom having more energy and being less stable.