212° F – temperature at which water boils

Gravity – the force that draws things toward the center of the earth

32° F – freezing and melting point of water / ice

Hail – frozen raindrops that have been blown back into the cloud to form more frozen layers

Air mass – a large body of air that has the same temperature and humidity

Humidity – the amount of water vapor in the air

Atmosphere – layer of air surrounding the earth, extending 1,000 miles, its weight

creates air pressure

Matter – anything that takes up space and has weight

Condensation – the process of changing water vapor into liquid water

Molecules – the smallest piece of a substance that still has the qualities of that substance

Dew point – the temperature water condenses

Nimbus – a storm or rain cloud

Energy – the ability to do work

Nitrogen – the gas that makes up most of the air

Evaporation – the process by which liquid water becomes water vapor

Precipitation – any form of water that falls from clouds to earth

Fog – a cloud on the ground

Snow – frozen water vapor formed in clouds

Force – the push or pull on an object

Water

1. covers ¾ of the earth

2. made of hydrogen and oxyge

Surface tension – the tight fitting together of water molecules near the water’s surface;

because water has a high surface tension, objects will float in it

Three States of Matter – you will be given a list of things to identify as either solid,

liquid or gas

1. solid

• molecules are packed close together
• molecules vibrate but do not move from place to place
• has a definite shape

1. liquid

• molecules are spread out
• molecules vibrate rapidly and move around one another
• has no shape of its own, but will take on the shape of a container

1. gas

• molecules are very spaced apart
• has the fastest moving molecules
• has no shape of its own and does not fill up a fixed amount of space

Heat causes molecules to move more rapidly.

The energy in steam comes from heat.