5-3 Matter and Mass

Scientists define the word matter as "anything that takes up space."  Everything takes up space except a vacuum.  A vacuum is the absence of matter.

Scientists measure how much matter there is in a thing.  As an example, a glass of milk has more matter than a glass filled with air.  You know this because the glass filled with milk weighs more than the glass filled with air.  You also know that a puppy weighs less than its mother.

Since weight changes from place to place, problems occur in trying to measure the amount of matter by how much it weighs.  You weigh more on earth than you would on the moon.  Did you know you also weigh less on top of a mountain than you do at sea level?  However, you still have the same amount of matter!

Scientists use the word "mass" to measure the amount of matter a thing at rest has no matter where it is located.  Unlike weight, the mass of a thing  (at rest) is always the same.  Your mass will be the same if you are on earth or floating in space and don't weigh anything at all!

Directions: Answer the questions to help you better understand the concept of "mass."

Scientists define matter as

a vacuum
anything that takes up space

Scientists use the word "mass"

to measure the amount of matter a thing at rest has no matter where it is located.
to define a vacuum

Which of the following statements is true?

  The mass of a thing at rest is always the same. 
  The matter of a thing is always the same no matter where it is located.

Everything takes up space except a .

A is the absence of matter.