Chemistry Semester Exam

What is the basic building block for all matter?

• Atom

• Element

• Molecule

• Compound

What is a substance consisting of a single type of atom called?

• Element

• Atom

• Molecule

• Compound

Which of the following is an example of an element?

• Oxygen

• Water

• Carbon Dioxide

• Sulfuric Acid

What is a molecule?

• A chemical substance formed when two or more different elements bond in a specific proportion

• The smallest unit that still keeps the properties of the compound

• The recipe for a chemical substance

• A shorthand that scientists use to describe a chemical reaction

How are chemical bonds formed?

• By sharing or exchange of protons

• By sharing or exchange of neutrons

• By sharing or exchange of electrons

• By sharing or exchange of atoms

What does a chemical formula tell us?

• The number of atoms of each element in a compound or molecule

• The number of valence electrons in an atom

• The number of molecules in a compound

• The number of protons in an atom

What is a chemical equation?

• A chemical substance formed when two or more different elements bond in a specific proportion

• The recipe for a chemical substance

• The smallest unit that still keeps the properties of the compound

• A shorthand that scientists use to describe a chemical reaction

How many hydrogen molecules are there in the chemical equation 2H₂ + O₂ > 2H₂O?

• 6

• 4

• 8

• 2

How many oxygen molecules are there in the chemical equation 2H₂ + O₂ > 2H₂O?

• 6

• 4

• 8

• 1

What is a pure substance?

• A simple combination of materials

• A substance with a definite and constant composition

• A substance consisting of a single type of atom

• A chemical substance formed when two or more different elements bond in a specific proportion