Answer:
Two liquids mix and release an odour
.
Two liquids form a precipitate
.
Step-by-step explanation:
If the two liquids mix and release an odour, that is a sign that a new substance has formed — a chemical change.
Similarly, if two liquids mix and form a precipitate, a new substance has formed — another chemical change.
B is wrong. The mixing of two colours is a physical change. The coloured substances don’t change. Our eyes just combine the two colours into a new one.
C is wrong. When a liquid boils and forms bubbles of gas, the substance changes from the liquid to the liquid gaseous state, but it is still the same substance. Boiling is a hysical change.
