States of Matter
Changes in State
100

What is a state of matter that has a definite volume but no definite shape?

Liquid.

100

____ ___ is the temperature that liquid boils. 

Boiling point. 

200

The ____ is a measure of the average speed of particles in a substance. 

Temperature.

200

What happens when liquid freezes? 

The particles slow and take fixed positions. 

300

Viscosity is the inward force among the molecules of a liquid.

Surface tension.


300

Vaporation is the reverse of condensation. 

True.

400

The ___ of a gas is the force of its outward push divided by the area of the walls of its container. 

Pressure.

400

What is it called when the surface particles of a gas form a solid.

Sublimation.

500

An amorphous solid has a definite melting point. 

Crystalline.

500

What two processes both happen at the surface of a substance? 

Evaporation and sublimation.