What’s an atom?

Atoms are the basic building blocks of all matter that make up everything--a chair, the air, and even you are made up of atoms. There are 94 different types of atoms that are formed naturally. Scientists have been able to create about 25 atoms synthetically in a lab.

For quite awhile, the atom was thought to be the smallest part of matter that could exist, but in the latter part of the 19th century and early part of the 20th, scientists discovered atoms are composed of certain subatomic particles. No matter what the element, the same subatomic particles make up the atom. Only the number of the particles varies from atom to atom.

Scientists now recognize that there are many subatomic particles, but we will focus on the three major subatomic particles: protons, neutrons, and electrons.

There are over 100 elements in the periodic table. The thing that makes each of those elements different is the number of protons, neutrons, and electrons. The protons and neutrons are always in the center of the atom--the nucleus. The electrons are always found whizzing around the center in areas called orbitals.

The subatomic particles have different charges. Protons have a positive charge, electrons have a negative charge, and neutrons have no charge. You know when you get a shock from static electricity? That’s a type of electric charge. If the charge of the entire atom is 0, that means there are equal numbers of positive and negative pieces, equal numbers of electrons and protons.