Discovery Education

Substance

A substance is any form of matter - solid, liquid, gas, or plasma. Water is a substance that naturally exists in solid, liquid, and gas form. In the Sun's core, at extremely high temperatures, ionized hydrogen is in the form of plasma

State of Matter

Ice in a glacier, water in a lake, and water vapor in the atmosphere are all water. On Earth, water exists in each of the three states of matter. The three states are solid, liquid, and gas. Everything on earth exists in at least one state of matter.

Stream

Since every animal needs water to live, many make their homes near a stream. A stream is a small, flowing body of water that begins as a spring and usually ends at a river. Animals, such as beavers, use the stream for protection as well as a source of food.

Melting Point

Take some an ice cubes in a beaker and heat it. After some time, you will see water beginning to form. If you put a thermometer into the beaker, it will show a reading of 32 degrees Fahrenheit until all the ice melts. The temperature at which ice starts turning to water is called the melting point of ice. All solids have melting points. If a solid has a high melting point, you will need a lot of heat to melt it.

Matter

The table that you just bumped into is made of solid matter. Things that take up space and have mass are called matter. You interact with matter everyday and everywhere you go. Now, take a deep breath and blow up this balloon. You just filled the balloon with matter. Gas in the balloon is matter. Liquids that you drink every day are also matter

Volume

Volume is the amount of space an object or substance takes up. There are different ways for measuring the volume of differently shaped objects. For objects with a regular shape, volume is measured by multiplying three dimensions. It is expressed in cubic units.

Boiling Point

Water gains energy when it is heated. Bubbles appear in the water and vapor or steam begins to rise. This temperature at which water begins to change from a liquid to a vapor is its boiling point.

Water Vapor

When water is heated, it becomes a gas. This gas is called water vapor, or steam. When water vapor is cooled, it turns into water again.

Freezing Point

When water is placed in a freezer, it becomes ice. As water cools, the molecules lose their energy. Their movement slows down and they finally freeze in place. The temperature at which water changes from a liquid to a solid state is its freezing point.

Dissolve

When you add the sugar and stir, it looks like the sugar has disappeared. Take a sip. Yes, it is sweet. The sugar has dissolved into the tea, which makes the tea sweet

Physical Change

You can melt ice and then refreeze the water to make ice again. The ice changes states but it is always water. You can tear up a piece of paper and it's still paper. You can mix sugar in water and still taste that the sugar is there. These are all physical changes. Physical changes mean that matter has changed states but remains the same.