Properties of Matter
A book is matter. Your pencil is matter. Your desk is matter. Matter
is anything that has mass and takes up space. The mass of an object
is how much matter it has. Heavier objects have more mass. Lighter
objects have less mass. Pick up a ball. It is matter. The air inside a ball
takes up space. It is matter too.
A property is something about matter that you can observe with
one or more of your senses. Shape, color, weight, size, smell, and taste
are some properties. A book might have a smooth cover and a square
shape. These are properties of that book.
Parts of Matter Have you ever used aluminum foil? Aluminum foil is matter made from particles of the element aluminum. An
element is matter made from a single type of particle that is too small
to see. Cut aluminum foil into many tiny pieces. Each piece is still
made of aluminum. Matter can be made up of one element or more
than one element. A penny is matter. Pennies used to be made only
of copper. They were pure copper, meaning there were no other elements in pennies except for copper. Now, pennies are made up of two
elements: copper and zinc.
All matter is made up of atoms. An atom is the smallest particle
of matter that has the properties of an element. Atoms are very
small. You cannot see them with your eyes or a regular microscope.
Scientists form images of them using special microscopes.
Look at a picture in a magazine. The colors appear to be solid.
Now, look at the same picture under a microscope. All the many
colors are made out of patterns of tiny dots of only a few colors. The
dots combine to make the colors in the picture. Different kinds of
matter are made up of combinations of atoms in the same way. Some
types of matter have a set ratio of elements. For example, a molecule
of water (H2O) is always made up of 2 hydrogen atoms and 1 oxygen
atom.
Ideas About Matter People have always wondered about
their world. In ancient times, people observed fire turn wood to ash.
Gas and smoke rose from the fire. Gas in the air turned to water and
rain. They concluded that earth, air, fire, and water were the four elements that made up all matter. Today, scientists know there are more
than 100 elements. Matter can be made up of one element, two elements, or many kinds of elements. Living things are mostly made up
of carbon, oxygen, nitrogen, and hydrogen.
The periodic table is a chart that scientists use to organize
all the elements. Each element has a name and a symbol. Some
people who have discovered elements have been allowed to
suggest names for them. Berkelium was named after the city of
Berkeley, California. What do you think californium is named
after? Einsteinium is named after Albert Einstein. Seaborgium is
named after another scientist, Glenn Seaborg. What would you
call an element named after you?
What Forms Does Matter Take? Matter can exist
in three forms: solid, liquid, and gas. The particles in these three
forms of matter are always moving. The particles move differently
in each form of matter. A baseball is a solid. It keeps its shape
when it flies through the air or rolls on the ground. Its particles
are firmly held together. They vibrate, but they stay in place.
Milk is a liquid. Its shape depends on what container is holding
it. The same amount of milk in a glass and in a carton will have a
different shape. The particles in a liquid are loosely held together.
They can flow past one another.
Gas particles are not held together. They move freely and
bounce off each other. Air is a gas. It does not have its own shape.
When you pump air into a ball, the air fills the space.