You are boiling water to cook some noodles. You notice bubbles forming on the bottom of the pot. Your brother thinks it is a chemical change. Is he correct?

They can measure  the amount of energy gained or lost

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.