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Gas Definition

A gas is a form of matter that can be invisible. For example, boiling water turns into water vapor, a gas.

View Lesson on Conservation of Matter
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Conservation of Matter

Fun Facts

  • Dry ice turns from solid to gas without becoming liquid first.
  • Burning sugar and baking soda releases gases, forming an expanded 'snake'.
  • Burning candle wax changes into carbon dioxide and water vapor gases.

Why Do We Need To Know About Gas

Learning how water changes from liquid to gas helps us understand evaporation. This is very important for cleaning water to make it pure. This process is key for creating energy to power things.

Knowing about gas and what it can do can lead to different jobs. On food making, evaporation makes tastes stronger. In studying the environment, scientists focus on how carbon moves around. These examples show how gas is very useful in everyday life and in business around the world.

Frequently Asked Questions

When the team mix 25 grams of sugar into 150 grams of water, the sugar seems to disappear! Where does it go?
The sugar dissolves into the water. It is still there, it simply changes into a form we can't see.
What evidence tells us that the sugar is still there, even though we can’t see it?
The sugar water weights 175 grams which is the same as all the sugar (25g) plus all the water (150g). This is evidence that the sugar is still there even though we can’t see it.
When Dr. Jeff boils the sugar water, what happens?
As the water is heated it changes forms from liquid to gas. The sugar is left behind as a solid, providing us with evidence that it was in there the whole time.
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