Question

list any four changes around us, which by observation can help us to determine whether a chemical reaction has occurred​

Answer 1

the change in colour of the object

evolution of gas

change in components

rusting of iron

burning wood

hope it helps

Answer 2

burning of candle

burning of paper

rusting of iron

souring of grapes

making of food

burning of wood
The following are the changes :
-change in colour
-change in state
-formation of new product
-evolution of gas