Physical Science Chapter 4 Review

Chemistry is

• the study of matter and how matter changes.

• anything that has mass and takes up space.

• a characteristic of a substance that can be observed without changing the substance into another substance.

• a rapid reaction between oxygen and a substance called a fuel.

The only sure evidence for a chemical reaction is

• changes in properties.

• the production of one or more new substances.

• the formation of a gas.

• a color change.

Which is the correct chemical equation for the following statement? Sodium reacts with oxygen in a 2 to 1 ratio to produce sodium oxide.

• Na₂ + O₂ → Na₂O₂

• 4 Na + O₂ → 2 Na₂O

• 2 Na + O₂ → 2 NaO

• Na₂O + O₂ → 2 NaO

In chemical reactions, what does the principle of conservation of mass mean?

• The total mass of the reactants is less than the total mass of the products.

• Matter is not changed.

• Matter is not created or destroyed.

• The total mass of the reactants is greater than the total mass of the products.

Chemicals that act as biological catalysts by speeding up reactions in living things are called

• enzymes.

• inhibitors.

• fuels.

• reactants.

A bottle of hydrogen peroxide that eventually turns into a bottle of water and oxygen gas is an example of a

• decomposition reaction.

• synthesis reaction.

• replacement reaction.

• precipitate reaction.

What type of reaction is FeS + 2 HCl → FeCl₂ + H₂S?

• decomposition reaction.

• synthesis reaction.

• double replacement reaction.

• single replacement reaction.

A shorter, easier way to show a chemical reaction, using symbols instead of words, is called a

• symbol.

• chemical formula.

• subscript.

• chemical equation.

The substances listed on the left side of a chemical equation are the

• products.

• coefficients.

• precipitates.

• reactants.

A chemical reaction that absorbs energy in the form of heat is described as

• combustion.

• endothermic.

• exothermic.

• unbalanced.