9.04.9 Keywords

· Nucleus – Centre of the atom

· Shells – Areas of the atom around the nucleus

· Proton – Positive subatomic particle found in nucleus

· Neutron – Neutral subatomic particle found in nucleus

· Electron – Negative subatomic particle found in shells

· Atomic Number – Number of protons in nucleus

· Mass Number – Number of protons + neutrons in nucleus

· Isotopes – Different versions of the same element (with extra neutrons)

· Abundance - % of each type of isotope of an element

· Relative Atomic Mass – Average mass of atoms of an element taking their abundance into account

· Nanometre – a billionth of a metre

· Electronic Structure – How the electrons are divided between shells (2.8.8 etc)

· Plum Pudding Model – First modern model of atom (positive atom with electrons scattered inside)

· Alpha Particle – Small positive particle smaller than atom

· Gold Leaf Experiment – Scattering alpha particles through Gold foil

· Nuclear Model – model of atom that has a small positive nucleus

· Bohr – scientist who showed the existence of shells

· Chadwick – scientist who proved existence of neutrons