Module 3: Chemical patterns

Module 3: Chemical patterns

Candidates will be assessed throughout this module on their ability to:

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

The structure of atoms
Candidates will be assessed on their ability to:

describe the structure of an atom as a nucleus containing protons and neutrons, surrounded by orbiting electrons arranged in shells (3.01)

Element and the periodic table
Candidates will be assessed on their ability to:

recall that there are about 100 elements in the periodic table arranged in order of ascending atomic number and recall that elements are the �building blocks� of all materials (3.02)

recall the position of metals and non-metals in the periodic table (3.03)

locate the positions in the periodic table of

� the alkali metals

� the halogens

� the noble gases (3.04)

understand how the electron shells are filled in the atoms of the first twenty elements in the periodic table, e.g. potassium 2.8.8.1 (3.05)

understand the connection between the number of outer electrons and the position of an element in a group of the periodic table (3.06)

understand that the reactions of an element depend upon the arrangement of electrons in its atoms (3.07)

recall that there is a gradual change in properties of the elements from the top to the bottom of each group (3.08)

understand that elements in the same group of the periodic table have similar chemical properties, as exemplified by the halogens (3.09)

The properties of halogens
Candidates will be assessed on their ability to:

recall that fluorine, chlorine, bromine and iodine are halogens (3.10)

recall the variation in colour, the trends in boiling point and the physical states at room temperature, of the halogens (3.11)

describe the reactions of chlorine with sodium and iron (3.12)

describe the variation in reactivity of the halogens with increasing atomic number, as shown by displacement reactions with solutions of other halides (3.13)

describe the use of chlorine in

� water purification

� bleaching (3.14)

recall the use of iodine solution as an antiseptic (3.15)

Rates of reaction
Candidates will be assessed on their ability to:

recall that there is great variation in the rates at which different reactions take place (3.16)

understand that the rate of chemical reaction increases if

� the temperature is increased

� the concentration of reactant is increased

� the surface area of a solid reactant is increased

� a catalyst is used (3.17)

describe experiments to investigate the above effects (3.18)

understand that reactions can occur when particles collide (3.19)

understand that the rate of a reaction is increased by

� increased frequency of the collisions

� greater energy of the collisions (3.20)

describe how the rates of enzyme catalysed reactions vary with temperature and pH (3.21)