|There are about 2.5 centimeters (cm) in one ____.
|A proton and a neutron have about the same ____ (1 amu).
|The process of a gas changing to a liquid is ____.
|A ____ is a little more than a quart.
|The study of light is called ____.
|A ____ converts chemical energy into electrical energy.
|A ____ is about 2.2 pounds (lb).
|A ____ is subatomic particle with a single positive charge.