List the observations that helps us to determine when a chemical reaction has taken place. [3 MARKS]
Each point: 1 Mark
1. Change in state and colour.
2. Evolution of a gas
3. Change in temperature.
Which of the following observations help us to determine whether a chemical reaction has taken place or not?
(i) Change in state.
(ii) Change in colour.
(iii) Change in shape
(iv) Evolution of gas.
(v) Change in temperature.
How do we come to know that a chemical reaction has taken place
write any 2 observations in an activity which may suggest that a chemical reaction has taken plas with examples