These topics are examined in the IAL Unit 3 for Edexcel Economics.
You can find notes for Unit 3 here:
The Firm and its Objectives
a) Objectives
b) Size of businesses
Revenue, Costs and Profit
a) Revenue
b) Costs
c) Economies and diseconomies of scale
d) Profit
Market Structures and Contestability
a) Perfect competition
b) Monopolistic competition
c) Oligopoly
d) Monopoly
e) Monopsony
f) Contestability
Government Intervention to Promote Competition
ab) Government intervention to protect consumers, suppliers and employees
c) Government intervention to promote international competitiveness
d) Government policy towards transnational companies (TNCs)