Gases in the Atmosphere Crossword Puzzle

QUESTIONS LIST:

• air : this is a mixture of gases in the atmosphere.
• nitrogen : gas needed to make protein and makes up 78% of the air.
• evaporation : when water turns into water vapor.
• condensation : when water cools and forms clouds.
• gas : state of matter which moves about freely.
• argon : makes up 0.93% of the air.
• precipitation : when water falls to the earth as rain
• collection : when water is collected in rivers, oceans and lakes.
• carbon dioxide : gas needed for photosynthesis and makes up 0.04% of the air.
• oxygen : gas needed for breathing and makes up 21% of the air.
• water cycle : process that recycles the water in the atmosphere over and over again.