Question

what do these two changes have in common? firing a clay pot in a hot kiln rust forming on a metal gate select all that apply. both are only physical changes. both are chemical changes. both are caused by heating. both are caused by cooling.

Explanation:

A chemical change is a process where one or more substances are transformed into new substances with different properties. Firing a clay pot in a hot kiln causes chemical reactions (e.g., dehydration, vitrification). Rust forming on a metal gate is a chemical reaction (oxidation of iron). Physical changes only change the form, not the substance. Heating causes firing (kiln heat) and rusting (temperature - related in the sense of reaction kinetics, though rusting is more about oxygen and moisture, but in the context of the options, compared to cooling, heating is relevant as kiln is hot).

Answer:

Both are chemical changes. Both are caused by heating.