What is an Atom?

The least you should know about atoms.

All matter in the universe is made of atoms.

Atoms are the smallest unit of matter that can be manipulated chemically.

Atoms are made of electrons, protons and neutrons.

A molecule is a group of atoms bonded together.

Chickens and cats are made of atoms.

An atom consists of a nucleus, surrounded by 1 or more electrons. The electrons are held to the nucleus by the electrostatic force. The electrostatic force is the same as the static electricity that makes your socks stick to your sheets in the dryer.

*whole mess of atoms falling from the sky*

Protons and electrons both carry an electric charge. The electrostatic force works the same way magnets do in that like charges repel and opposite charges attract. Protons are positive (+1) and electrons are negative (-1.) Usually an atom has a similar number of electrons and protons meaning that it is electrically neutral. The charges of the electron and the proton offset each other. I tend to visualize them as tiny little magnets. They aren’t magnets, they are electric in nature, but it helps me to imagine how they interact.

For example, helium has 2 protons (charge is +2) and 2 electrons (charge is -2) so the net
charge is 0. Since like charges repel and opposite charges attract, an electrically neutral atom is also electrically stable. It has no excess electrical charge to attract or repel other atoms. The net charge of differnt atoms play an important role when atoms bond with each other. Bonding is essential because it is what makes molecules and molecules make everthing. Water is a molecule of two hydrogen atoms bonded to one oxygen atom.