Atomic Structure - AS AQA unit 1

Atomic Structure.

Protons: mass of 1, relative charge of +1

Neutrons: mass of 1, relative charge of 0

Electrons: mass of 5.4x10-4, relative charge of -1

mass number: total number of protons plus neutrons.

atomic number is the number of protons in the nucleus.

isotopes: elements of the same number of electrons and protons (same atomic number) but different mass number, so different number of neutrons. 

number of neutrons = mass number - atomic number.

properties of an isotopes:

• same atomic number
• different neutron number
• rate of diffusion is different
• different …