Structure Of Matter

What is matter?

Is a glass with some water in it half empty or full? Actually, neither is correct. The glass is completely full, half full of water and half full of air. What is air? Air is a mixture of several gases. Including nitrogen and oxygen, which are kind of matter. Matter is anything that has mass and take up space. So, even though you can not see it or hold it in your hand, air is matter. What about all the things you can see, taste, smell and touch? Most are made of matter, too.

What is not matter?

Does light have mass and take up space? What about the warmth from the sun or heat from the heater in your classroom? Light and heat do not take up space, and they have no mass. Therefore, they are not forms of matter. Emotions, thoughts, and ideas are not matter either.

Atom

The word "atom" comes from the Greek "atomos", indivisible. The first person we know used the word "atom" is the Greek philosopher Democritus, around 400 BC. Atoms are incredibly tiny particles that make up all substances. There are 92 types of atom one for each of the 92 elements that exist naturally. Each type of atom has different properties (e.g., size or mass). All solids, liquids, and gases are made of atoms. Atoms are very small, but their exact size depends on the type. Atoms range from 0.1 to 0.5 nanometres in width. One nanometre is about 100,000 times smaller than the width of a human hair. This makes one atom impossible to see without special tools.

Parts of Atom

An atom is made up of three main particles the proton, the neutron and the electron.

Rule

All atoms have at least one proton, one neutron, and one electron each

Exceptions to the rule

Hydrogen-1, an isotope of hydrogen, has no neutrons, just the one proton and one electron. A positive hydrogen ion has no electrons, just one proton. These two examples are the only exceptions to the rule