Chemistry AQA AS EXAM 2024 QUESTIONS WITH 100% CORRECT ANSWERS

Mass number - ANSWERS Total number of protons and neutrons. Atomic number - ANSWERS Numbers of protons in the nucleus and number of electrons in shells. Negative Ions - ANSWERS More electrons than protons. Positive ions - ANSWERS More protons than electrons. Relative isotopic mass - ANSWERS mass of an atom of an isotope of an element on a scale where an atom of carbon12 is 12. Relative atomic mass - ANSWERS average mass of an atom of an element on a scale where an atom of carbon12 is 12. Relative molecular mass - ANSWERS average mass of a molecule on a scale where an atom of carbon12 is 12. First ionisation energy - ANSWERS the energy needed too remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions. Second ionisation energy - ANSWERS the energy needed to remove 1 electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions. Number of particles= - ANSWERS Number of moles x Avagadros constant (6.02 x 10^23) Number of moles= - ANSWERS Mass / Mr Number of moles= - ANSWERS Concentration (moldm^-3) x Volume (dm^3) Methyl orange indicator - ANSWERS yellow in acid, red in alkali. Commonly used in titrations. Phenolphthalein indicator - ANSWERS pink in alkali, colourless in acid. Commonly used in titrations. Avogadros constant - ANSWERS the number of atoms in 12g of carbon12 (6.02 x 10^23) Ideal gas equation - ANSWERS Pv= nRT Empirical formula - ANSWERS simplest whole number ratio of atoms of each element in a compound. Molecular formula - ANSWERS gives the actual numbers of each element in a molecule. Percentage yield - ANSWERS how much product was actually made compared with the amount of product that was expected theoretical yield - ANSWERS the maximum mass of product expected in a reaction. actual yield - ANSWERS the mass of product that is actually obtained in a reaction. Atom economy - ANSWERS measure of the efficiency of a chemical reaction. The proportional mass of reactants that actually become part of the desired product in a balanced chemical equation.