Module 10: Understanding chemical reactions

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You should be able to: (high tier in bold)
recall the formulae of elements and simple compounds in the module
represent chemical reactions by word equations; write simple balanced equations and use
the state symbols (s), (l), (g) and (aq)
write balanced equations to describe and explain a wide range of reactions including
ionic equations

Atoms and isotopes
You should be able to:
10.01 recall that all atoms of the same element have the same number of protons
10.02 recall the relative charges and relative masses of protons, neutrons and electrons
10.03 understand the terms atomic number and mass number
10.04 understand that isotopes are atoms of the same elements with the same number of protons
and electrons, but different numbers of neutrons
10.05 calculate the relative atomic mass of an element from relative masses and abundances
of its isotopes

Chemical bonds
You should be able to:
10.06 recall that some elements combine by means of chemical reactions to form compounds, for example, water, carbon dioxide, sodium chloride and iron sulfide
10.07 recall that an ion is an atom or group of atoms with a positive or negative charge
10.08 recall that ionic bonds are formed between atoms of a metal and a non-metal, for example,
sodium and chlorine forming sodium chloride
10.09 recall that chemical bonding involves the transfer or sharing of electrons
10.10 explain the formation of simple ionic compounds (for example, sodium chloride) in terms of
transfer of electrons
10.11 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
10.12 describe and explain the physical properties of giant ionic structures, including sodium
chloride and magnesium oxide
10.13 recall that covalent bonds are formed between atoms of some non metals to produce
molecules (including hydrogen, nitrogen, oxygen, chlorine and hydrogen chloride)
10.14 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
10.15 describe the physical properties of simple molecular compounds
10.16 understand that covalent bond formation can result in simple molecules (eg hydrogen,
iodine) and giant structures (eg diamond and graphite)
10.17 describe and explain the differences between the physical properties of simple
molecular substances and those with giant molecular structures

Energy transfers
You should be able to:
10.18 recall that changes of temperature often accompany reactions
10.19 recall that an exothermic reaction is one in which thermal energy is given out
10.20 recall that an endothermic reaction in one in which thermal energy is taken in
10.21 understand that the breaking of bonds is endothermic and that the making of bonds is
exothermic

Using chemical equations
You should be able to:
10.22 calculate the relative formula masses of simple compounds, given relative atomic masses
10.23 use chemical equations quantitatively to determine the masses of substances used and
produced
10.24 determine the empirical formulae of simple compounds from reacting masses