(a)[1]
Chemical reactions may be endothermic or exothermic. State the meaning of endothermic.
(b)[1]
Deduce which fuel, P, Q, R or S, gives the smallest energy release per gram.
(c)[1]
Name one gas that is used as a fuel.
(d)[1]
Complete the diagram with these words: products, reactants.
(e)[1]
State one further use of radioactive isotopes.