Atoms and Elements

Atoms and Elements

1. In the atom

   • The Nucleus
     • in the middle of the atom
     • contains protons and neutrons
     • has a positive charge overall
     • tiny compared to the rest of the nucelus
   • Electrons
     • negatively charged
     • orbit the nucleus in shells

2. Atoms have no charge overall because the negative charge of the electrons cancels out the positive charge of the protons.

3. Number of protons = Number of electrons

4. If some electrons are added or removed, the atom becomes charge and is then an ion

5. Elements are made up of atoms. When 2 or more atoms join together a molecule is formed

   • The atoms in elements are held tightly to each other by chemical bonds