IS7 - Unit 7 Test

Chemical equations are balanced by changing _______________ in an equation, not the _______________ of the molecules.

• coefficients; subscripts

• subscripts; coefficients

• molecules; atoms

• elements; compounds

_______________ is needed to break bonds in chemical reactions.

• Energy

• Water

• Pressure

• Light

A chemical reaction in which more energy is absorbed than is released is _______________.

• endothermic

• exothermic

• neutralization

• combustion

_______________ chemical reactions occur at the same rate.

• Equilibrium

• Spontaneous

• Exothermic

• Endothermic

_______________ is the minimum amount of energy needed for a chemical reaction to begin.

• activation energy

• kinetic energy

• potential energy

• thermal energy

Exothermic reactions, like most other reactions, require _______________ energy to begin.

• activation

• kinetic

• potential

• thermal

An equation is _______________ when it contains the same number of atoms on both the reactant and the product side.

• balanced

• unbalanced

• neutral

• reactive

_______________ the temperature slows down most chemical reactions; _______________ the temperature will speed most reactions up.

• increasing, decreasing

• decreasing, increasing

• setting, adjusting

• adjusting, setting

Water boiling, aluminum foil crumbling, and glass shattering are all examples of _______________ changes. Wood burning is an example of a _______________ change.

• physical; chemical

• chemical; physical

• physical; physical

• chemical; chemical

Each substance, such as a chemical, written to the left of the arrow in a chemical equation is called a _______________.

• reactant

• product

• catalyst

• solvent