AS Chemistry - Atomic Structure

Atomic Number:- the number of protons in an atom

Mass Number:- the number of protons and neutrons in an atom

Isotopes:- atoms of the same element with the same number of protons but different numbers of neutrons

Weighing Atoms:- standard mass = 1/12th mass of one atom of carbon 12

Relative Isotopic Mass:- mass of one atom of an isotope relative to 1/12th of one carbon 12 atom

Relative Atomic Mass:- weighted average mass of one atom, relative to 1/12th mass of one atom of carbon 12

Relative Molecular Mass:- weighted average mass of one molecule relative to 1/12th of one atom of carbon 12

1st Ionisation energy:- energy required to remove 1 electron from each atom is 1 mole of atoms of an element

Mass Charge Protons 1 +1 Neutrons 1 0 Electrons 1/2000 -1 Protons and Neutrons are found in the nucleus, Electrons found around the outside of the nucleus at different energy levels.