Equilibrium

5. a change involving the creation of a new substance
7. a system in balance but where forwards and backwards reactions occur at the same rate
9. the chemicals involved in a reaction surroundings everything except the chemicals involved in a reaction
10. a change where no new substance is created
11. a system in balance

1. a reaction where the products can be converted back to the reactants
2. heat energy which is either absorbed or released in the breaking and making of chemical bonds during a reaction
3. the minimum amount of energy required in order for a reaction to occur
4. a transition or intermediate state formed during a reaction as a precursor to the product, but which has a high energy and so is relatively unstable
6. where one or more reactants or products in a reaction can be either added or lost physical change
8. where the chemicals involved in a reaction are all contained within a fixed space