The Structure of an atom
-atoms are made up of protons neutrons and electrons.
- the nucleus of an atom contains protons and neutrons
- the electrons are found at large distances from the nuceus.
- proton charge- +1 relative mass- 1
- Electron change : -1 relative mass- 1/1836
- Neutron charge: 0 relative mass- 1
Atomic number= number of protons in an atom
Mass number= proton number + number of neutrons
Neutron number= mass number - proton/atomic number
Number of neutrons in an atom can vary slightly eg:
there are three kinds of carbon: carbon-12 carbon-13 carbon-14.
They all have SAME number of PROTONS (atomic number) but the number of NEUTRONS vary!
these different forms of the same elements are called ISOTOPES