Chemical reactions

Which one of the following is a characteristic of a chemical change?

• Light being given off

• Change of state

• Change of shape

• Change of size

Which one of the following is a characteristic of Physical change?

• Light being given off

• Heat being given off

• Bubbles appearing

• Change of state

What is an exothermic reaction?

• Heat is taken in from the external environment by the chemical reaction and temperature decreases

• Heat is given off to the external environment by the chemical reaction and the temperature increases.

What is an endothermic reaction?

• Heat is taken in from the external environment by the chemical reaction and temperature decreases

• Heat is given off into the external environment by the chemical reaction and temperature increases

What are the chemicals entering a chemical reaction called?

• Reactors

• Reactants

• Products

• Elements

What are the chemicals made as a result of a chemical reaction called?

• Reactors

• Reactants

• Products

• Elements

What does the arrow labelled A represent?

• Product energy

• Activation energy

• Reactant energy

• Final energy

What kind of thermal reaction is A?

• Endothermic

• Exothermic

What kind of thermal reaction is B?

• Endothermic

• Exothermic

What is meant by 'rate of reaction'?

• The amount of time for the reactants to begin reacting

• The amount of energy spent on reacting

• The about of time for a reaction to take place

• The amount of time it takes for energy to be conserved