Question

question 5. which of the following is not a chemical change?
rusting of iron.
converting water into steam.
making curd from milk.
heating coal.

Explanation:

A chemical change results in a new substance being formed. Rusting of iron forms iron - oxide, making curd from milk changes milk proteins, and heating coal can lead to combustion products. Converting water into steam is a physical change as water changes from liquid to gas state without forming a new chemical substance.

Answer:

Converting water into steam