42 UG008982 � Specification � Edexcel GCSE in Science: Single, Double, Separate Sciences B �

recall the formulae of elements and simple compounds in the module

represent chemical reactions by word equations; write simple balanced equations and usethe state symbols (s), (l), (g) and (aq)

write balanced equations to describe and explain a wide range of reactions including ionic equations

recall that all atoms of the same element have the same number of protons (10.01)

recall the relative charges and relative masses of protons, neutrons and electrons (10.02)

understand the terms atomic number and mass number (10.03)

understand that isotopes are atoms of the same elements with the same number of protons and electrons, but different numbers of neutrons (10.04)

calculate the relative atomic mass of an element from relative masses and abundances of its isotopes (10.05)

recall that some elements combine by means of chemical reactions to form compounds, for example, water, carbon dioxide, sodium chloride and iron sulfide (10.06)

recall that an ion is an atom or group of atoms with a positive or negative charge (10.07)

recall that ionic bonds are formed between atoms of a metal and a non-metal, for example, sodium and chlorine forming sodium chloride (10.08)

recall that chemical bonding involves the transfer or sharing of electrons (10.09)

explain the formation of simple ionic compounds (for example, sodium chloride) in terms of transfer of electrons (10.10)

describe the structure of ionic compounds as a lattice structure, consisting of a regular arrangement of ions, held together by strong forces between them, forming crystals (10.11)

describe and explain the physical properties of giant ionic structures, including sodium chloride and magnesium oxide (10.12)

recall that covalent bonds are formed between atoms of some non metals to produce molecules (including hydrogen, nitrogen, oxygen, chlorine and hydrogen chloride) (10.13)

explain the formation of simple covalent molecules (eg hydrogen, hydrogen chloride, water, methane, carbon dioxide) in terms of shared electrons between non-metal atoms, using dot and cross diagrams (10.14)

describe the physical properties of simple molecular compounds (10.15)

understand that covalent bond formation can result in simple molecules (eg hydrogen, iodine) and giant structures (eg diamond and graphite) (10.16)

describe and explain the differences between the physical properties of simple molecular substances and those with giant molecular structures (10.17)

recall that changes of temperature often accompany reactions (10.18)

recall that an exothermic reaction is one in which thermal energy is given out (10.19)

recall that an endothermic reaction in one in which thermal energy is taken in (10.20)

understand that the breaking of bonds is endothermic and that the making of bonds is exothermic (10.21)

calculate the relative formula masses of simple compounds, given relative atomic masses (10.22)

use chemical equations quantitatively to determine the masses of substances used and produced (10.23)

determine the empirical formulae of simple compounds from reacting masses (10.24)