1. The Structure of an Atom
Atomic Theory
The Structure of an Atom

2. The Parts of an Atom The Proton The Neutron The Electron
The atom is made of 3 distinct particles
The Proton
The Neutron
The Electron

3. The Proton p+ Location Charge Mass Symbol
The Proton is found in the centre of the atom called the Nucleus
Charge
The Proton has a positive charge [+]
Mass
The Proton has a mass of 1 amu.
Symbol p+

4. The Neutron no Location Charge Mass Symbol
The Neutron is found in the centre of the atom called the Nucleus
Charge
The Neutron has no charge [o]
Mass
The Neutron has a mass of 1 amu.
Symbol no

5. The Electron e- Location Charge Mass Symbol
The Electron is found in paths moving outside the nucleus.
Charge
The Electron has a negative charge [-]
Mass
The Electron has a mass of 0 amu. (1/1850 amu)
Symbol e-

6. The Structure of an Atom

7. Summary
{ COMPLETE THIS TABLE }
PARTICLE SYMBOL LOCATION CHARGE MASS

8. Facts about Atoms Atoms have equal numbers of protons and electrons.
No. of Protons = No. of Electrons.
The number of protons is called the
Atomic Numbers
Elements are arranged in the periodic table in order of increasing Atomic Number.
amu = atomic mass unit.

9. Examples Hydrogen : H : Atomic No.1 = 1p+ 1e- Helium : He :
{Complete the examples}
Hydrogen : H : Atomic No.1 = 1p+ 1e-
Helium : He :
Aluminium : Al :
Chlorine : Cl :