8.6 8.6 Matter and energy.

Na

S

N

So

Melting ice

Burning wood

Tearing paper

Dissolving sugar in water

Oxygen

Carbon

Nitrogen

Hydrogen

Mass is lost during the reaction.

Mass is gained during the reaction.

Mass remains constant during the reaction.

Mass is irrelevant in chemical reactions.

1

2

3

4

Silicon

Iron

Gold

Helium

It involves a change in state.

It involves the rearrangement of atoms to form new substances.

It involves a change in temperature.

It involves a change in color.

$$6CO_2 + 6H_2O \rightarrow C_6H_{12}O_6 + 6O_2$$

$$C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O$$

$$6CO_2 + 6H_2O \rightarrow 6O_2 + C_6H_{12}O_6$$

$$6O_2 + C_6H_{12}O_6 \rightarrow 6CO_2 + 6H_2O$$

Formation of a covalent compound

Formation of an ionic compound

No reaction occurs

Formation of a metallic compound

Yes, because the number of each type of atom is the same on both sides.

No, because there are more molecules on the right side.

Yes, because the total number of molecules is the same.

No, because the equation is not balanced.