1. Ch. 4 Vocabulary – States of Matter
(p. 123, 11 terms + 7)

2. 1. States of Matter
The physical forms of matter, which include solid, liquid, and gas.

3. 2. Solid
The state of matter in which the volume and shape of a substance are fixed.

4. 3. Liquid
The state of matter that has a definite volume but not a definite shape.

5. 4. Gas
A form of matter that does not have a definite volume or shape.

6. 5. Plasma
In physical science, a state of matter that starts as a gas and then becomes ionized; it consists of free-moving ions and electrons, it takes on an electric charge, and its properties differ from the properties of a solid, liquid, or gas.

7. 6. Change of State
The change of a substance from one physical state to another.

8. 7. Melting
The change of state in which a solid becomes a liquid by adding heat.

9. 8. Evaporation
The change of state from a liquid to a gas.

10. 9. Boiling
The conversion of a liquid to a vapor when the vapor pressure of the liquid equals the atmospheric pressure.

11. 10. Condensation
The change of state from a gas to a liquid.

12. 11. Sublimation
The process in which a solid changes directly into a gas.

13. 12. Atom
The smallest unit of an element that maintains the properties of that element.

14. 13. Molecule
A group of atoms that are held together by chemical forces; a molecule is the smallest unit of matter that can exist by itself and retain all of a substance’s chemical properties.

15. 14. Melting Point
The temperature at which a substance changes from a solid to a liquid.
(A physical property/ characteristic property used to identify substances – melting point of water = 0°C).

16. 15. Freezing
The change of state from a liquid to a solid.

17. 16. Freezing Point
The temperature at which a liquid changes into a solid.
(A physical property/ characteristic property used to identify substances – freezing point of water = 0°C).

18. 17. Boiling Point
The temperature at which a liquid changes into a vapor, or gas.
(A physical property/ characteristic property used to identify substances – boiling point of water = 100°C).

19. 18. Condensation Point
The temperature at which a gas becomes a liquid.
(A physical property/ characteristic property used to identify substances – condensation point of water = 100°C).

20. Grading Scale (1 point per term) A = 18 - 17 B = 16 - 15 C = 14 - 13
F = 10 or less