# Physical Properties

## Conductor

In order for an object or material to be considered a conductor, it needs to be able to conduct, or transmit heat/electricity. For example, certain types of metals, such as nickel or cobalt, are good conductors of electricity.

## Insulator

An insulator is the opposite of a conductor. Instead of allowing electricity to flow through freely, it blocks it. Insulators don't conduct heat or electricity. The reason why wires are often coated with rubber, is because rubber is a good insulator. They don't allow the electricity to go through it, therefore you can touch the wire without fear of an electrical shock.

## Mass

Mass is referring to the amount of matter an object is made of. People often confuse mass with weight, but your weight can change depending where you are. For instance, you would weigh less on the moon then you do on Earth. Your mass, however, doesn't change, no matter where you are! Mass can be measured using a balance.

## Density

Density is the compactness of a substance. It's how "tightly packed" something is. Things with a higher degree of density are more "tightly packed" than things with a lower degree of density. Water can be used to test density. If the object is denser than the water, it will sink, but if it is less dense than the water, it will float.

## Buoyancy

Buoyancy is the upward push of a liquid on an object placed in it. It is the reason why things float or sink. Density goes along with buoyancy, because if the object is too dense, the push of the liquid is not strong enough to keep it floating.