Unit 2 Review

A model of a chemical compound is shown. What is the correct way to write the formula for this compound?

• 2HO

• ₂H₂O

• H₂O₂

• HO²

In a chemical formula, ______________ is used to indicate the number of atoms of each element.

Anything that has mass & takes up space

• gravity
• force
• matter
• volume

Substances that form as the result of a chemical reaction

• products
• reactants
• coefficients
• subscripts

Substances present at the start of a chemical reaction

• subscripts
• coefficients
• reactants
• products

• 2

• 3

• 5

• 6

The Law of Conservation of Mass says that matter can neither be __________ or __________.

• created; destroyed

• recycled; renewed

• subtracted; added

• joined; separated

• 7

• 10

• 17

• 20

According to the Law of Conservation of Mass, what happens to the wood and oxygen when it is burned?

• The wood disappears.

• It stays the same chemically.

• The atoms in the wood and oxygen rearrange and form smoke and ash.

• Nothing.

A 55-gram egg is placed in a pot. After the egg is boiled, which is most likely the mass of the egg?

• 50 
• 55