Atomic Structure

Atomic Structure

1. A PROTON has a mass of 1 and a charge of +1. A NEUTRON has a mass of 1 and a charge of 0. An ELECTRON has a mass of almost 0 with a charge of -1

2. The number of electrons in an atom is always the same as the number of protons

3. Atoms can lose or gain electrons. When they do, they form charged particles called ions

   • if an atom loses one or more electrons, it becomes a positively charged ion
   • if an atom gains one or more electrons, it becomes a negatively charged ion

4. The atomic number of an atom is the number of protons it contains.The mass number of an atom is the total number of protons and neutrons it contains.