Structure of the Atom

The Atom The atom is the smallest part of any element that

retains all of the properties of that element. The atom is made up of:

protons (+)electrons (-)neutrons (0)

The central core of the atom is called the nucleus, containing protons and neutrons. (Nucleus charge = +)

The Atom

PROTONS

# protons = atomic #

The Atom

ELECTRONS

# electrons = # protons

The Atom

NEUTRONS

# neutrons = atomic mass -

atomic #

In your notebook, determine the number of protons, electrons, and neutrons for the following elements:

Oxygen Argon Magnesium Neon Nitrogen Chlorine

Protons Neutrons Electrons

8 8 8

18 22 18

12 12 12

10 10 10

7 7 7

17 18 17

The Atom

The electrons are located in energy levels around the nucleus.

Electron Fill Rule (2-8-8 rule) Electrons fill energy levels as follows

– First Energy Level = 2 electrons– Second Energy Level = 8 electrons– Third Energy Level = 8 electrons

Let’s Practice

Oxygen Argon Magnesium Neon Nitrogen Chlorine

http://www.chemicalelements.com/