What is Chemistry?

1. What is chemistry?

a. A pseudo-science developed to torture students
b. The study of numbers and formulas
c. The study of matter and how it behaves
d. The study of intergalactic forces

2. What is matter?

a. Nothing. So far so good.
b. An object with strange, unknowable behaviors
c. The "stuff" that makes up the world around us, including us
d. Tiny particles that exist only in outer space

3. What is an atom?

a. A small subunit that makes up matter and that is important to understanding the behavior of matter
b. A term to collectively describe all the matter in the universe
c. A large piece of matter that is not important to understanding the behavior of matter
d. None of the above

4. What determines how matter behaves?

a. No one knows! This is the great mystery of the universe.
b. The behavior of matter is unpredictable.
c. The behavior of matter is predictable and is determined by what is happening at an atomic level.
d. None of the above.

5. Why are chemists interested in the behavior of matter?

a. They seek world domination right alongside with Pinky and the Brain.
b. They seek to understand the world around them in order to predict and control certain outcomes.
c. They seek to control all matters of the universe.
d. None of the above.

Matter

1. Which of the following does NOT represent a physical change?

a. Liquid water is frozen to make ice cubes
b. Sweat evaporates from skin
c. Sugar reacts with oxygen gas to form carbon
d. Gaseous water condenses on the sides of a cool soda can to make water droplets

2. True/False. In a physical change, the identity of a chemical changes.

3. A chemical change is best described as...

a. A change where a substance changes color
b. A change where an explosion occurs
c. A change where a substance changes its state of matter
d. A change where a new substance is formed

4. True/False. An example of a physical change is the sublimation of carbon dioxide where solid carbon dioxide goes directly into the gaseous phase.

5. Which of the following represents a physical change?

a. Acid rain reacting with metal
b. A block of ice melting to make a pool of water
c. A metal reacting with water in the air
d. Two gases reacting to form a solid

Elements

1. An element is best defined as...

a. A collection of various types of atoms.
b. A substance formed by a mixture of chemical compounds.
c. A pure substance.
d. A small subunit of matter.

2. What is a chemical compound?

a. A single atom of a single element
b. A single element of matter
c. At least two atoms of at least two different elements joined together
d. At least three atoms of different elements joined together

3. True/False. Elements combine together to make an atom.

4. True/False. An element, such as carbon, is composed of multiple different atoms, like oxygen and hydrogen atoms.

5. True/False. Water, H₂O, is an element.

Atoms

1. Which of the following atomic particles has a negative charge?

a. Neutron
b. Nucleus
c. Proton
d. Electron

2. Which of the following atomic particles has a positive charge?

a. Neutron
b. Electron
c. Proton
d. Nucleus

3. Which of the following atomic particles make up the nucleus?

a. Protons and neutrons
b. Electrons and protons
c. Neutrons and electrons
d. Neutrons only

4. Which subatomic particle(s) can be found in the space surrounding the nucleus?

a. Neutrons
b. Protons
c. Electrons
d. Both protons and electrons

5. Which of the following subatomic particle is responsible for much of the chemistry that we "see?"

a. Neutrons
b. Protons
c. Electrons
d. Both protons and electrons

The Periodic Table

1. The atomic number of any given element corresponds to the number of _________________ in an atom of that element.

a. neutrons
b. nuclei
c. electrons
d. protons

2. Which of the following bits of information about an element appears on the periodic table?

a. The number of electrons present in one atom of that element
b. The number of protons present in one atom of that element
c. The date of discovery of the element
d. Common chemical compounds made by that particular element

3. How is the periodic table organized with respect to atomic numbers?

a. The atomic numbers decrease as you move from top to bottom along a column.
b. The atomic numbers decrease as you move from left to right.
c. The atomic numbers increase as you move from bottom to top.
d. The atomic numbers increase as you move from left to right.

4. What is a chemical family?

a. A group of elements that can generally be found by moving from left to right along a given row of the periodic table.
b. A group of elements that can generally be found by moving from right to left along a given row of the periodic table.
c. A group of elements that can generally be found by following a vertical column in the periodic table.
d. None of the above.

5. Which of the following elements has three protons?

a. Lithium
b. Helium
c. Carbon
d. Nitrogen

Bonding & Chemical Reactions

1. In the chemical equation below, what is the product of the reaction?
Fe + S → FeS

a. Fe
b. S
c. Fe + S
d. FeS

2. Which subatomic particle plays an important role in bonding between atoms?

a. Protons
b. Neutrons
c. Electrons
d. Quarks

3. True/False. In a chemical reaction, new bonds between atoms form.

4. What is a reactant?

a. A chemical that is formed as a result of a chemical reaction
b. A chemical involved in a physical change
c. A chemical involved in a chemical change that must be present at the start of a chemical reaction
d. A chemical that is present for a chemical reaction, but does not take part in the reaction; it is unchanged

5. How can we tell which chemical symbols represent the reactants in a chemical equation?

a. Reactants are always on the left side of the arrow in a chemical equation.
b. Reactants are always on the right side of the arrow in a chemical equation.
c. Reactants are placed in bold in a chemical equation.
d. A chemical equation does not contain sufficient information for us to determine the reactants. We must see the reaction take place.

Lab Tips

1. Who should wear goggles during a lab experiment?

a. Contact-wearers need goggles to protect their contact lenses.
b. Persons who wear glasses need to substitute goggles for their glasses.
c. All individuals, regardless of whether they are wearing glasses or not, need to use goggles. Persons who are wearing glasses need to wear goggles over their glasses.
d. No one needs to wear goggles. Eyeballs have a tendency to grow back if damaged.

2. Is glassware with a crack ever safe to use in a lab experiment?

a. No.
b. It depends. If the crack is very small, the glassware is probably not going to break.
c. Yes, as long as you discard the glassware after the experiment.
d. None of the above.

3. True/False. It is safe to modify a lab procedure by substituting materials if you don't quite have what you need on hand.

4. When should hair be tied back and kept out of the face for lab experiments?

a. Never. We should always strive to look our best for lab. For some of us that means hair down and free!
b. Always.
c. Sometimes. If working with an open flame, hair should be back. Otherwise, it is Okay to keep it down.

5. What type of shoes should we wear for labs?

a. Flip-flops
b. High heels
c. Birkenstocks
d. Close-toed shoes

Answers

What is Chemistry?

1. What is chemistry?

c. The study of matter and how it behaves

Chemistry is a scientific discipline that focuses on matter and the behavior of matter.

2. What is matter?

c. The "stuff" that makes up the world around us, including us

Matter is all around us. Everything we can see is made up of matter. There is also matter that we cannot see, such as the oxygen in the air.

3. What is an atom?

a. A small subunit that makes up matter and that is important to understanding the behavior of matter

An atom is defined as a small subunit of matter. Understanding how atoms are attracted to one another helps explain the overall behavior of matter.

4. What determines how matter behaves?

c. The behavior of matter is predictable and is determined by what is happening at an atomic level.

Understanding how atoms are attracted to one another helps explain the overall behavior of matter.

5. Why are chemists interested in the behavior of matter?

b. They seek to understand the world around them in order to predict and control certain outcomes.

Scientific knowledge allows us to understand the world in novel ways as well as predict, and in some instances, control, the behavior of matter.

Matter

1. Which of the following does NOT represent a physical change?

c. Sugar reacts with oxygen gas to form carbon

Any time you see the key word "react," you know that a chemical change has taken place. This is the only answer in which a new substance is formed during the transformation: the new substance is carbon.

2. True/False. In a physical change, the identity of a chemical changes.

False. The identity of a chemical stays the same during a physical change. It is simply changing from one state into another.

3. A chemical change is best described as...

d. A change where a new substance is formed

A chemical change occurs when a new substance is formed.

4. True/False. An example of a physical change is the sublimation of carbon dioxide where solid carbon dioxide goes directly into the gaseous phase. 

True. Sublimation is an example of a physical change because the identity of the chemical (in this case, carbon dioxide) does not change.

5. Which of the following represents a physical change?

b. A block of ice melting to make a pool of water

This is the only answer where a reaction does not take place. The water is simply changing from solid to liquid form.

Elements

1. An element is best defined as...

c. A pure substance

An element is a pure substance. For our purposes in this introduction, all of the atoms in an elemental sample are identical in composition.

2. What is a chemical compound?

c. At least two atoms of at least two different elements joined together

A chemical compound consists of atoms from at least two different types of elements. We need at least two different atoms to build a chemical compound.

3. True/False. Elements combine together to make an atom.

False. Atoms of elements combine together to make chemical compounds.

4. True/False. An element, such as carbon, is composed of multiple different atoms, like oxygen and hydrogen atoms.

False. An element consists of identical atoms of that particular element.

5. True/False. Water, H₂O, is an element.

False. Water is made of two different elements: hydrogen and oxygen.

Atoms

1. Which of the following atomic particles has a negative charge?

d. Electron

Electrons are always negatively charged.

2. Which of the following atomic particles has a positive charge?

c. Proton

Protons are always positively charged.

3. Which of the following atomic particles make up the nucleus?

a. Protons and neutrons

The nucleus is composed of protons and neutrons.

4. Which subatomic particle(s) can be found in the space surrounding the nucleus?

c. Electrons

Electrons surround the space around the nucleus. They occupy what scientists call, "electron clouds" in the atom.

5. Which of the following subatomic particle is responsible for much of the chemistry that we "see?"

c. Electrons

Atoms can lose, gain, and share electrons. The nucleus of an atom is generally stable and does not change.

The Periodic Table

1. The atomic number of any given element corresponds to the number of _________________ in an atom of that element.

d. protons

The number of protons that an atom contains determines its chemical identity.

2. Which of the following bits of information about an element appears on the periodic table?

b. The number of protons present in one atom of that element

The number of protons present is equivalent to the atomic number.

3. How is the periodic table organized with respect to atomic numbers?

d. The atomic numbers increase as you move from left to right.

The periodic table is organized such that atomic numbers increase as you move from left to right along any given row of the periodic table.

4. What is a chemical family?

c. A group of elements that can generally be found by following a vertical column in the periodic table.

Many columns in the periodic table indicate chemical families. There are some notable exceptions, such as a large block of elements that are found in the middle of the periodic table, but we will get to those in a later chapter.

5. Which of the following elements has three protons?

a. Lithium

Using a periodic table, we see that the atomic number for lithium is three, meaning that lithium atoms all contain three protons.

Bonding & Chemical Reactions

1. In the chemical equation below, what is the product of the reaction?Fe + S → FeS

d. FeS

FeS, or iron sulfide, is the product of the chemical reaction shown above. Products are always found on the right hand side of the arrow in a chemical equation.

2. Which subatomic particle plays an important role in bonding between atoms?

c. Electrons

Electrons are involved in chemical bonding and consequently, chemical reactions.

3. True/False. In a chemical reaction, new bonds between atoms form.

True. Chemical reactions are a result of bonding changes where atoms are rearranged to form new chemicals.

4. What is a reactant?

c. A chemical involved in a chemical change that must be present at the start of a chemical reaction.

A reactant is required for a chemical reaction to occur. It often "reacts" with another chemical or it may decompose. In either case, the atoms making up the reactant rearrange to form a new substance.

5. How can we tell which chemical symbols represent the reactants in a chemical equation?

a. Reactants are always on the left side of the arrow in a chemical equation.

By convention, chemists always place reactants on the left side of the arrow in a chemical equation.

Lab Tips

1. Who should wear goggles during a lab experiment?

c. All individuals, regardless of whether they are wearing glasses or not, need to use goggles. Persons who are wearing glasses need to wear goggles over their glasses.

Everyone wears goggles. It's as simple as that.

2. Is glassware with a crack ever safe to use in a lab experiment?

a. No.

Don't ever use glassware that contains a crack. It poses a safety hazard.

3. True/False. It is safe to modify a lab procedure by substituting materials if you don't quite have what you need on hand.

False. Always ask the teacher if you have questions about a procedure or the materials/equipment used in the procedure.

4. When should hair be tied back and kept out of the face for lab experiments?

b. Always.

Always pull hair back. It is most obviously a safety hazard when working with an open flame, but it is also a safety hazard anytime we are working with chemicals.

5. What type of shoes should we wear for labs?

d. Close-toed shoes

Always protect toesies from falling glassware and hot substances.