Question 1

A physical change
A) occurs when iron rusts.
B) occurs when sugar is heated into caramel.
C) occurs when glucose is converted into energy within your cells.
D) occurs when water is evaporated.
E) occurs when propane is burned for heat.

Accepted Answer

A physical change occurs when water is evaporated. The physical state of water changes from liquid to gas, but the chemical composition of water remains the same. Iron rusting (A) and sugar being heated (B) are both examples of chemical changes, where the composition of the substance changes. Glucose being converted into energy (C) is a biological process and not a physical change. Propane being burned (E) is also a chemical change where it reacts with oxygen to produce carbon dioxide and water.

Question 2

Two or more substances in variable proportions,where the composition is constant throughout are
A) a compound.
B) an element.
C) a heterogeneous mixture.
D) a homogeneous mixture.
E) a crystalline solid.

Accepted Answer

A homogeneous mixture is a type of mixture in which the composition is uniform throughout, and it consists of two or more substances in variable proportions. Examples of homogeneous mixtures include solutions, alloys, and some forms of gas mixtures. The composition of a homogeneous mixture is constant throughout, which distinguishes it from a heterogeneous mixture where the composition can vary from one part to another.

Question 3

Identify a gas.
A) definite volume and definite shape
B) definite volume and no definite shape
C) definite shape and no definite volume
D) no definite shape and no definite volume

Accepted Answer

Gases have no definite shape and no definite volume; they expand to fill the container they are in.

Question 4

Which of the following statements about the phases of matter is TRUE?
A) In both solids and liquids, the atoms or molecules pack closely to one another.
B) Solids are highly compressible.
C) Gaseous substances have long-range repeating order.
D) There is only one type of geometric arrangement that the atoms or molecules in any solid can adopt.
E) Liquids have a large portion of empty volume between molecules.

Accepted Answer

Both solids and liquids have atoms or molecules that are close together, but in solids, the arrangement is highly ordered, while in liquids, the arrangement is more random. Solids are also not highly compressible, unlike gases. Gaseous substances do not have long-range repeating order, and there are many geometric arrangements that atoms or molecules in solids can adopt. Liquids do not have a large portion of empty volume between molecules.

Question 5

Identify a liquid.
A) definite volume and definite shape
B) definite volume and no definite shape
C) definite shape and no definite volume
D) no definite shape and no definite volume

Accepted Answer

Liquids have definite volume but no definite shape, meaning they take the shape of the container they are in. Option A describes a solid, option C describes a solid with a specific shape, and option D describes a gas.

Question 6

A substance that can't be chemically broken down into simpler substances is
A) a homogeneous mixture.
B) an element.
C) a heterogeneous mixture.
D) a compound.
E) an electron.

Accepted Answer

An element is a substance that cannot be chemically broken down into simpler substances. Elements are made up of atoms with the same number of protons in their nucleus.

Question 7

Which of the following statements is TRUE?
A) A scientific law is fact.
B) Once a theory is constructed, it is considered fact.
C) A hypothesis is speculation that is difficult to test.
D) An observation explains why nature does something.
E) A scientific law summarizes a series of related observations.

Accepted Answer

A scientific law is a statement that summarizes a pattern of observations, while a theory is a well-supported explanation for the behavior of nature. A hypothesis is an idea or prediction that can be tested through experimentation or observation, and observations simply describe what is seen in the natural world. Therefore, option E is the correct statement as it correctly defines a scientific law.

Question 8

Which of the following represents a hypothesis?
A) Sodium reacts with water to form sodium hydroxide and hydrogen gas.
B) Nitrogen gas is a fairly inert substance.
C) Nickel has a silvery sheen.
D) When a substance combusts, it combines with air.
E) When wood burns, heat is given off.

Accepted Answer

A hypothesis is a proposed explanation for a phenomenon, which can be tested through experimentation or observation. Option D suggests a testable explanation for the process of combustion.

Question 9

Filtration is
A) a process in which the more volatile liquid is boiled off.
B) dissolving a solid into a liquid.
C) separating a solid from a liquid by pouring off the liquid.
D) pouring a mixture through a filter paper to separate the solid from the liquid.
E) heating a mixture of two solids to fuse them together.

Accepted Answer

Filtration involves pouring a mixture through a filter paper that allows the liquid to pass through while retaining the solid. The solid remains on the filter paper, while the liquid passes through into the container below. This is a common technique used in chemistry to separate mixtures.

Question 10

Dalton's Atomic Theory states
A) that all elements have several isotopes.
B) that matter is composed of small indestructible particles.
C) that the properties of matter are determined by the properties of atoms.
D) that energy is neither created nor destroyed during a chemical reaction.
E) that an atom is predominantly empty space.

Accepted Answer

Dalton's Atomic Theory states that matter is composed of small indestructible particles called atoms. This was a significant advancement in our understanding of the nature of matter and laid the foundation for modern chemistry. The other options are not accurate descriptions of Dalton's Atomic Theory.

Question 11

Identify a solid.
A) definite volume and definite shape
B) definite volume and no definite shape
C) definite shape and no definite volume
D) no definite shape and no definite volume

Accepted Answer

A solid has a definite volume because the particles are tightly packed and have a fixed position. It also has a definite shape because the particles are arranged in a specific pattern and cannot move freely like in a liquid or gas.

Question 12

Molecules can be described as
A) mixtures of two or more pure substances.
B) mixtures of two or more elements that has a specific ratio between components.
C) two or more atoms chemically joined together.
D) heterogeneous mixtures.
E) homogeneous mixtures.

Accepted Answer

Molecules are formed when two or more atoms chemically combine together through covalent bonds. Therefore, molecules are not mixtures and they are composed of specific elements in a fixed ratio.

Question 13

Two or more substances in variable proportions,where the composition is variable throughout are
A) a solution.
B) a homogeneous mixture.
C) a compound.
D) an amorphous solid.
E) a heterogeneous mixture.

Accepted Answer

A heterogeneous mixture is a combination of two or more substances in variable proportions where the composition is not uniform throughout. This contrasts with a homogeneous mixture or solution, where the components are evenly distributed and the composition is constant throughout. A compound is a substance made up of two or more different elements chemically bonded together in a fixed proportion, while an amorphous solid is a solid that lacks long-range order and has no well-defined shape or structure.

Question 14

A scientific theory
A) is just a theory.
B) is a strict set of rules and procedures that lead to inarguable fact.
C) isn't used much in modern chemistry.
D) is based on continued observation and experiment.
E) is a framework for proving an argument you know to be true.

Accepted Answer

A scientific theory is not just a guess or a hypothesis, but a well-tested and supported explanation for a phenomenon or set of observations based on continued observation and experiment. It is not a set of rules or procedures that lead to inarguable fact, nor is it a framework for proving an argument you already know to be true. While it may not be used explicitly in every aspect of chemistry, theories are crucial to the scientific method and are used across many scientific fields.

Question 15

Distillation is
A) a process in which the more volatile liquid is boiled off.
B) dissolving a solid into a liquid.
C) separating a solid from a liquid by pouring off the liquid.
D) pouring a mixture through a filter paper to separate the solid from the liquid.
E) heating a mixture of two solids to fuse them together.

Accepted Answer

Distillation is a process of separating two or more substances by vaporizing and condensing the more volatile component. The process involves boiling a mixture to create vapor, which is then condensed back into a liquid and collected separately. The more volatile liquid is boiled off, leaving behind the less volatile liquid or solid.

Question 16

The statement,"In a chemical reaction,matter is neither created nor destroyed" is called
A) the Law of Conservation of Mass.
B) Dalton's Atomic Theory.
C) the Scientific Method.
D) the Law of Multiple Proportions.
E) the Law of Definite Proportions.

Accepted Answer

The statement "In a chemical reaction, matter is neither created nor destroyed" is known as the Law of Conservation of Mass. This law was proposed by Antoine Lavoisier in the late 18th century after observing that the total mass of reactants and products in a closed system remained constant. This law is a fundamental principle of chemistry and is used to balance chemical equations.

Question 17

Identify the TRUE statement.
A) Hydrogen peroxide is used as rocket fuel and removes color from hair.
B) Hydrogen peroxide can be used as a drink and can be used to bathe in.
C) Both water and hydrogen peroxide are stable molecules.
D) Water reacts with skin.
E) Hydrogen peroxide is smaller than water.

Accepted Answer

Hydrogen peroxide is indeed used as a propellant in rocketry due to its ability to rapidly decompose into water and oxygen in the presence of a catalyst, providing thrust. It is also used in hair bleaching processes to remove color. The other statements contain inaccuracies: hydrogen peroxide should not be ingested, water and hydrogen peroxide have different stability profiles with hydrogen peroxide being less stable, water does not react with skin in a harmful way, and hydrogen peroxide (H2O2) is larger than water (H2O) due to the extra oxygen atom.

Question 18

A substance composed of two or more elements in a fixed,definite proportion is
A) a homogeneous mixture.
B) a heterogeneous mixture.
C) a compound.
D) a solution.
E) an alloy.

Accepted Answer

A substance composed of two or more elements in a fixed, definite proportion is a compound. The other options do not fit the definition of a compound.

Question 19

Decanting is
A) a process in which the more volatile liquid is boiled off.
B) dissolving a solid into a liquid.
C) separating a solid from a liquid by pouring off the liquid.
D) pouring a mixture through a filter paper to separate the solid from the liquid.
E) heating a mixture of two solids to fuse them together.

Accepted Answer

Decanting involves separating a solid from a liquid by pouring off the liquid, leaving behind the solid. The process does not involve boiling, dissolving, filtering, or fusing of solids.

Question 20

Which of the following statements about crystalline and amorphous solids is TRUE?
A) A crystalline solid is composed of atoms or molecules arranged with long-range repeating order.
B) An example of a crystalline solid is glass.
C) An example of an amorphous solid is table salt (NaCl).
D) An amorphous solid is composed of atoms or molecules with a majority of its volume empty.
E) All of the above statements are TRUE.

Accepted Answer

Crystalline solids are defined by having atoms or molecules arranged in a long-range repeating pattern, while amorphous solids lack this ordered arrangement. Glass, while often mistaken for an amorphous solid, is actually a type of non-crystalline solid with a unique atomic arrangement. Table salt, on the other hand, is an example of a crystalline solid with a highly ordered arrangement of Na+ and Cl- ions. Option D is incorrect as amorphous solids are still composed of atoms or molecules with no significant portion of empty space.

Quiz 1: Matter, measurement, and Problem Solving

A physical change

Two or more substances in variable proportions,where the composition is constant throughout are

Identify a gas.

Which of the following statements about the phases of matter is TRUE?

Identify a liquid.

A substance that can't be chemically broken down into simpler substances is

Which of the following statements is TRUE?

Which of the following represents a hypothesis?

Filtration is

Dalton's Atomic Theory states

Identify a solid.

Molecules can be described as

Two or more substances in variable proportions,where the composition is variable throughout are

A scientific theory

Distillation is

The statement,"In a chemical reaction,matter is neither created nor destroyed" is called

Identify the TRUE statement.

A substance composed of two or more elements in a fixed,definite proportion is

Decanting is

Which of the following statements about crystalline and amorphous solids is TRUE?