Atomic structure

sub-atomic particles and the 3 types

Smaller particles inside of the atoms

Three types are protons neutrons and electrons

What are the relative masses and charges

Proton

• Relative mass: 1

• Relative charge: +1

Neutron

• Relative mass: 1

• Relative charge: 0

Electron

• Relative mass: 0

• Relative charge: -1

Where are these subatomic particles located?

Protons - nucleus

Neutrons - nucleus

Electrons - shells surrounding the nucleus

Isotopes

Atoms with the same number of protons but different numbers of neutrons

How to find the number of neutrons

Mass number - atomic number

What’s the atomic number

The num of protons

What’s the mass number

The number of protons plus the number of neutrons

Number of electrons =

Num of protons

Radio isotopes

Unstable isotopes which spontaneously break up and emit radiation in the form of alpha particles, beta particles and gamma rays

Radio isotopes and their uses

• Na-24: used to trace the flow of blood and locate blockages in the circulatory system

• I-131: used for monitoring and treating thyroid

• Pu-238: provides energy for heart pace makers

• C-14: used in carbon dating where archeologists can find the actual age of specimens

• U-235: used as a source of energy in some nuclear power plants

Ions

atoms which become charged due to the loss or gain of electrons (e.g. cations (+) and anions (-))

Why do atoms form ions

So they can have a more stable electronic structure like that of a noble / inert gas