1. Solids, Liquids, and Gases 8th Grade Science
Chapter 3
Solids, Liquids, and Gases
8th Grade Science

2. States of Matter
Solids, liquids, and gases can be _________, __________, or ___________.
_________ - a definite shape and volume
Solids will keep their shape in any position and in any container
Particles of a solid are packed _________together
Particles of a solid ______ slightly – they are in constant motion.
Particles stay in the same position - ________ in place
elements
compounds
mixtures
Solid
Closely
vibrate
vibrate

3. Types of Solids
_____________ - particles in a regular, repeating pattern. Examples: sugar, salt, and snow.
Cyrstalline solids will _____ at a specific temperature.
_______________ - particles are not arranged in a particular pattern. Examples: plastics, rubber, and glass.
Amorphous Solids will _________ at a specific temperature – they may become softer and softer until they change into other substances. Example: butter.
Crystalline solids
melt
Amorphous solids
not melt

4. Liquids
______ - a definite volume and takes the shape of its container.
- particles of a liquid are packed almost as closely as a solid.
-particles move around more _____ than in a solid.
- no definite _____ but a definite ________.
______ - freely moving particles.
Liquids
freely
shape
volume
Fluid

5. Properties of Liquids
____________ - the result of an inward pull among the particles of a liquid that brings the particles on the surface closer together.
Water particles pull together and bead up on surfaces or form a skin – water striders walk on water due to surface tension
___________ - a liquids resistance to flowing.
Depends on the size and shape of the particles and the attractions between the particles.
Liquids with ______ viscosity flow ______ (honey)
Surface Tension
viscosity
high
Slowly

6. Gases
______ - can change volume , particles are spread out and free to move, no definite shape.
Particles of gas move in all directions.
As gas particles move, they fill the space around them
Particles of gas can be squeezed into a container. When the container is open, the particles will move freely and spread out.
Gas

7. Changes Between Solid and Liquid
Particles of a liquid have more ________ energy than particles of the same substance in solid form.
Particles of the same substance as a gas has even more _________ energy than the liquid or solid form.
A substance changes state when its thermal energy either _______ or __________ sufficiently.
thermal
thermal
increases
decreases

8. Melting
A change in state from a solid to a liquid involves the ________ in thermal energy.
___________ is the change in state from a solid to a liquid.
___________ - specific temperature at which the melting occurs.
At a substances ____________, the particles that are bound together begin to vibrate so rapidly that they break free from their fixed positions.
increase
Melting
Melting point
Melting point

9. Freezing __________ - the change of state from a liquid to a solid.
_________ of melting
____________ - the particles begin to move so slowly that they begin to form a regular pattern.
Example: water loses energy – water molecules move slowly because they lose energy until freezing is complete
Freezing
Reverse
Freezing Point

10. Changes between Liquid and Gas
____________ - the change from a liquid to a gas.
Particles gain enough _______ to form a gas.
___________ - vaporization that takes place only on the surface of a substance.
________ - vaporization that occurs when a liquid changes to a gas below the surface as well as at the surface of the liquid.
Vaporization
energy
evaporation
boiling

11. Boiling Point / Condensation
The __________ of a substance depends on the __________ of the air above.
The _______ the pressure, the ___ energy needed for the particles to escape into the air.
___________ - opposite of vaporization. Particles in a ___ lose enough energy to form a _____.
Boiling point
pressure
lower
less
Condensation
Gas
liquid

12. Changes between a Solid and a Gas
____________ - surface particles of a solid gain enough energy that they form a gas without passing through the liquid phase.
Example: dry ice (aka
Sublimation