AQA AS level Chemistry exam 2024 questions with 100% correct answers

Nucleons - ANSWERS Protons and neutrons Electrons (location) - ANSWERS Surrounding the nucleus Relative mass of an electron - ANSWERS 1/1840 Strong nuclear force - ANSWERS The way protons and neutrons are held together in the nucleus Electrostatic forces - ANSWERS The attraction between protons and electrons that hold them together in the atom Atomic Number (Z) - ANSWERS The number of protons in the nucleus Mass number (A) - ANSWERS The total number of protons and neutrons in the nucleus (the number of nucleons) Isotope - ANSWERS Same number of protons and electrons, but different number of neutrons Mass spectrometer - ANSWERS The most useful instrument for the accurate determination of relative formula mass Atomic orbital - ANSWERS A region of space around an atomic nucleus where there is a high probability of finding an electron Ionisation energy - ANSWERS The energy required to remove one mole of electrons from one mole of atoms in the gaseous state Relative atomic mass (Ar) - ANSWERS The weighted average mass of an atom of an element, taking into account its naturally occurring isotopes, relative to 1/12 the relative atomic mass of an atom of carbon-12 Relative molecular mass (Mr) - ANSWERS The mass of that molecule compared to 1/12 the relative atomic mass of an atom of carbon-12 Avogadro constant (the definition) - ANSWERS The number of atoms in 12g of carbon12 Avogadro's constant (the number) - ANSWERS 6.022 x 10^23 A mole - ANSWERS The amount of substance that contains 6.022x10^23 particles Ideal gas equation - ANSWERS PV=nRT Empirical formula - ANSWERS The formula that represents the simplest whole number ratio of the atoms of each element in a compound Molecular formula - ANSWERS the formula that gives the actual number of atoms of each element in one molecule of a compound Stoichiometry - ANSWERS The simple whole number ratios in which chemical species react Spectator ions - ANSWERS Ions that are unchanged during a chemical reaction, that is, they do not take part in the reaction Atom economy - ANSWERS Describes the efficiency of a chemical reaction by comparing the total number of atoms in the product with the total number of atoms in the starting materials