Download Atomic theory revision

Atomic theory revision
An atom is a particle that has no overall charge.
This is because the no. of protons (+) = no. of electrons (-)
The atom has 2 parts:
1. the nucleus
2. the shells
The atom consists of 3 sub particles, their properties are
summarised below:
Particle
location
Proton
nucleus
Neutron
nucleus
Electron
shells
Relative charge
+
Neutral
-
Relative mass
1
1
1/1840
11  atomic number
Na
23  atomic mass number
From the atomic number the number of protons = 11
As the no. of protons =
no of electrons = 11
The number of neutrons = mass number (23)- atomic number (11) = 12
Definitions you must learn:
Atomic number = the number of protons in
the nucleus OF AN ATOM
Mass number = the number of protons +
neutrons in the nucleus OF AN ATOM