1.
All matter is made up of atoms or molecules? True or False
Correct Answer
A. True
Explanation
All matter is made up of atoms or molecules. Atoms are the basic building blocks of matter, and molecules are formed when two or more atoms chemically bond together. Therefore, everything around us, including solids, liquids, and gases, is composed of atoms or molecules. Hence, the correct answer is true.
2.
Are atoms mostly full or mostly empty space?
Correct Answer
B. Mostly Empty Space
Explanation
Atoms are mostly empty space because they consist of a small, dense nucleus surrounded by electrons that occupy a larger volume. The nucleus contains protons and neutrons, which have mass and take up a small fraction of the atom's total volume. The electrons, on the other hand, are much smaller and move around the nucleus in specific energy levels. The vast majority of an atom's volume is therefore empty space, with the electrons occupying relatively small regions around the nucleus.
3.
What makes the atoms of one element different from the atoms of another element?
Correct Answer
A. The number of protons in the nucleus
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 element's identity and distinguishes it from other elements. The number of protons also determines the chemical properties of an element, as it determines the arrangement of electrons in the atom's electron shells. Therefore, the number of protons is what makes the atoms of one element different from the atoms of another element.
4.
How many naturally occuring elements are found?
Correct Answer
C. 92
Explanation
The periodic table consists of 118 known elements, out of which 92 are naturally occurring elements. Naturally occurring elements are those that are found in nature without being synthesized or created artificially. These elements are present in various proportions in the Earth's crust, atmosphere, oceans, and living organisms.
5.
A molecule does not need more than one element to be considered a "compound".
Correct Answer
B. False
Explanation
A compound is defined as a substance that is composed of two or more different elements chemically bonded together. Therefore, a molecule must contain more than one element in order to be considered a compound. If a molecule consists of only one element, it is referred to as an element or a pure substance, not a compound. Hence, the statement given in the question is false.
6.
It is possible to have a molecule that is not a compound...True or False
Correct Answer
A. True
Explanation
A molecule is a group of atoms bonded together, while a compound is a type of molecule that is made up of different elements. Therefore, it is possible to have a molecule that consists of only one type of element, such as oxygen gas (O2), which is not a compound.
7.
All compounds are molecules.
Correct Answer
A. True
Explanation
All compounds are molecules because compounds are formed when two or more atoms chemically combine, resulting in the formation of a molecule. A molecule is a group of atoms held together by chemical bonds. Therefore, every compound is composed of molecules, making the statement true.
8.
Is O2 a molecule?
Correct Answer
A. YES
Explanation
O2 is a molecule because it consists of two oxygen atoms bonded together. Molecules are formed when two or more atoms chemically combine, and in the case of O2, the oxygen atoms share electrons to form a stable molecule. Therefore, O2 meets the criteria of being a molecule.
9.
Is O2 a compound?
Correct Answer
B. NO
Explanation
O2 is not a compound because it consists of two oxygen atoms bonded together, making it a molecule. A compound is formed when different elements combine chemically. Since O2 is made up of only one type of element, it cannot be classified as a compound.
10.
How many compounds are in the following image?
Correct Answer
A. 2
Explanation
The image likely shows two distinct compounds.
11.
How many molecules are in the following image?
Correct Answer
B. 6
Explanation
The image shows 6 molecules.
12.
Is air a mixture or a pure substance?
Correct Answer
A. Mixture
Explanation
Air is considered a mixture because it is composed of various gases such as nitrogen, oxygen, carbon dioxide, and trace amounts of other gases. These gases are not chemically combined and can be separated from each other through physical means, such as by using fractional distillation. Therefore, air does not have a fixed composition and is classified as a mixture rather than a pure substance.
13.
Is baking soda (NaHCO3) a mixture or a pure substance?
Correct Answer
B. Pure substance
Explanation
Baking soda (NaHCO3) is a pure substance because it is a compound made up of a fixed ratio of sodium (Na), hydrogen (H), carbon (C), and oxygen (O) atoms. It has a definite and consistent composition, and its properties are consistent throughout. It cannot be separated into simpler substances by physical means, indicating its purity.
14.
Is apple juice a mixture or a pure substance?
Correct Answer
A. Mixture
Explanation
Apple juice is considered a mixture because it is composed of multiple substances that are not chemically combined. It is made by extracting the juice from apples, which contains a combination of water, sugars, vitamins, minerals, and other compounds. These components can be separated from each other through physical means, such as filtration or evaporation. Therefore, apple juice does not have a fixed composition and can vary depending on the variety of apples used and the processing methods employed, making it a mixture rather than a pure substance.
15.
Is Aluminum (Al) a mixture or a pure substance?
Correct Answer
B. Pure substance
Explanation
Aluminum (Al) is a pure substance. This is because it is a chemical element that cannot be broken down into simpler substances by physical or chemical means. It consists of only one type of atom, making it a homogeneous substance with uniform properties throughout.
16.
Is 100% pure orange juice a mixture or a pure substance?
Correct Answer
A. Mixture
Explanation
100% pure orange juice is a mixture because it is made up of different components. Orange juice contains water, sugars, acids, vitamins, minerals, and other compounds that make up its distinct flavor and nutritional profile. These components are not chemically bonded together and can be separated through physical processes such as filtration or evaporation. Therefore, orange juice is considered a mixture rather than a pure substance.
17.
Is blood a heterogeneous or a homogenous mixture?
Correct Answer
A. Homogeneous
Explanation
Blood is a homogeneous mixture because it is composed of multiple components, such as red blood cells, white blood cells, and plasma, that are uniformly distributed throughout the mixture. This means that the composition of blood is consistent throughout, with no visible separation or variation in its components.
18.
Is an oil and water mixture heterogeneous or a homogenous mixture?
Correct Answer
B. Heterogeneous
Explanation
The given correct answer is "Heterogeneous." An oil and water mixture is considered heterogeneous because it consists of two immiscible substances, oil and water, that do not mix evenly. Instead, they form distinct layers or phases within the mixture. This can be observed when oil and water are combined, and the oil floats on top of the water, forming separate layers.
19.
What is it called when multiple pure substances are added together?
Correct Answer
C. Mixture
Explanation
When multiple pure substances are added together, it is called a mixture. A mixture is formed when two or more substances are combined physically, without any chemical reaction taking place. In a mixture, the individual substances retain their own properties and can be separated by physical means, such as filtration or evaporation. This is different from a compound, where two or more elements chemically combine to form a new substance with different properties.
20.
What are the only two types of pure substances?
Correct Answer
A. Elements and compounds
Explanation
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, as they have distinct compositions and properties.
21.
Most of the hot flavor in peppers comes from capsaicin, C18H27NO3, Capsaicin is a(n)
Correct Answer
B. Pure substance
Explanation
The correct answer is pure substance because capsaicin is a specific chemical compound with a fixed composition and distinct properties. It is not an element because it is composed of multiple elements (carbon, hydrogen, nitrogen, and oxygen). It is not a diatomic molecule because it does not consist of two atoms of the same element bonded together. It is not a mixture because it is not a combination of different substances that can be physically separated.
22.
Changing the amount of energy or pressure will affect the states of matter
Correct Answer
A. True
Explanation
Changing the amount of energy or pressure can indeed affect the states of matter. Increasing the energy or pressure can cause a substance to change from a solid to a liquid or from a liquid to a gas, while decreasing the energy or pressure can cause the reverse to happen. This is because energy and pressure can affect the intermolecular forces between particles, causing them to either break apart or come closer together, resulting in a change in the state of matter. Therefore, the statement is true.
23.
Which of the following is not a state of matter?
Correct Answer
C. Condesate
Explanation
The given options are solid, gas, condensate, and liquid. Solid, gas, and liquid are all states of matter. Condensate, on the other hand, is not a state of matter. Condensate refers to a state of matter that occurs when a gas or vapor cools and transforms into a liquid. Therefore, condensate is not a separate state of matter but rather a transitional phase between gas and liquid.
24.
What is the following state of matter?
Correct Answer
C. Gas
Explanation
The given question asks for the state of matter that is being described. The options provided are solid, liquid, and gas. The correct answer is gas.
25.
The particles in a liquid and gas are always in motion but the particles in a solid stop moving?
Correct Answer
B. False
Explanation
The statement is false because particles in a solid do not stop moving completely. While the particles in a solid are closely packed and have limited freedom of movement, they still vibrate in fixed positions. This means that although they do not move around like particles in a liquid or gas, they are not completely stationary.
26.
When a substances goes from a solid to a liquid it is called….
Correct Answer
A. Melting
Explanation
When a substance goes from a solid to a liquid, it is called melting. This process occurs when heat is applied to the solid, causing the particles to gain energy and vibrate more rapidly. As a result, the attractive forces between the particles weaken, allowing them to move more freely and form a liquid state.
27.
When a substance goes from a gas to a solid it is called…
Correct Answer
B. Deposition
Explanation
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 decreases below its sublimation point, causing the gas molecules to lose energy and come together to form a solid. The other options, melting, sublimation, and freezing, involve different phase changes, but deposition specifically refers to the transition from gas to solid.
28.
What is dry ice going from a solid directly to a gas an example of?
Correct Answer
C. Sublimation
Explanation
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 passing through the liquid phase. In the case of dry ice, which is solid carbon dioxide, it undergoes sublimation when exposed to atmospheric pressure, causing it to change directly into a gas. This is why dry ice "disappears" and turns into a gas without leaving behind any liquid residue.
29.
Water found on the outside of a glass is called what?
Correct Answer
C. Condensation
Explanation
When water vapor in the air comes into contact with a cold surface, such as the outside of a glass filled with a cold drink, it loses heat and transforms into liquid water. This process is called condensation. So, the water found on the outside of a glass is called condensation.
30.
Do chemical or physical properties involve forming a new substance?
Correct Answer
A. Chemical
Explanation
Chemical properties involve the formation of a new substance. This means that when a chemical reaction occurs, the original substances react and rearrange their atoms to form new substances with different properties. This is different from physical properties, which do not involve a change in the chemical composition of a substance.
31.
When a substance changes from a liquid to a gas it loses mass.
Correct Answer
B. False
Explanation
When a substance changes from a liquid to a gas, it does not lose mass. The mass of a substance remains constant during the phase change. The change from liquid to gas is a physical change, where the substance's particles gain enough energy to break free from the attractive forces holding them together in the liquid state. However, the total mass of the substance remains the same, as no particles are lost or gained in the process.
32.
Is energy gained or lost during sublimation?
Correct Answer
A. Gained
Explanation
During sublimation, a substance transitions directly from a solid to a gas without passing through the liquid phase. This process requires energy input to break the intermolecular forces holding the solid together and to overcome the forces of attraction between the particles in the gas phase. Therefore, energy is gained during sublimation.