300+ AQA Chemistry A Level Practice Questions and Answers

What is the relative mass and charge on a proton? Mass 1 charge +1 What is the relative mass and charge on a neutron? Mass 1 Charge 0 What is the relative mass and charge on an electron? Mass 1/2000 Charge -1 What is the mass number? The total number of protons and neutrons in the nucleus of an atom What is the Atomic (proton) number? This is the number of protons in the nucleus of an atom and is used to identify an element What are Ions? Ion have different numbers of protons and electrons. Negative ions have more electrons than protons and positive ions have fewer electrons than protons. What are isotopes? Isotopes of an element are atoms with the same number of protons but different numbers of neutrons describe Thomson's model of the atom. Thomson's model of the atom was like a 'plum pudding' with a positively charged pudding (solid sphere) that contained negatively charged particles (electrons). What was found in Rutherford's gold foil experiment? When alpha particles were fired at a thin gold sheet, most of them passed straight through with a very small number deflected straight back. What was Rutherford's new nuclear model for the atom? A tiny positively charged nucleus at the centre, surrounded by a cloud of negative electrons. Most of the atom is empty space.