Chemical Reactions

In a ___________change, a substance changes into a different substance.

• Physical
• Chemical

Which of these is NOT a sign that a chemical change has occurred? 

• A loss of transparency 
• An unexpected color change
• A temperature change
• The formation of a precipitate

a copper penny turning greenish after a few years.

• Chemical Change
• Physical Change

An gel ice pack getting cold after you put it in the freezer for an hour.

• Chemical Change
• Physical Change

The Law of Conservation of Mass states

• that matter exists in all states and reacts the same
• that matter can only be changed into new substances by introducing a catalyst
• that matter exists in the same state throughout any chemical change
• that matter cannot be created or destroyed and that the mass of the products must equal the mass of the reactants

How many F atoms are in this compound?
6MgF₂ 

• 2
• 6
• 8
• 12

How many Al atoms are in this compound?         4Al₂O₃

• 2
• 8
• 6
• 4

The left side of the equation below is called

• Products

• Reactants

• Materials

• Ingredients

The right side of the equation below is called the

• products

• reactants

• materials

• ingredients

A number in front of a chemical formula in an equation that indicates how many molecules or atoms of each reactant and product are involved in a reaction.

• coefficient

• reactant

• subscript

• product