Who is correct? Reggie, because baking and melting cause bonds to be broken, leading to a chemical change. Reggie, because objects that are heated always undergo chemical changes. Charlotte, because melting objects only sometimes cause a chemical change. Charlotte, because baking causes a chemical change, but melting objects is a non-chemical change.

 Charlotte, because baking causes a chemical change, but melting objects is a non-chemical change.

Explanation: Baking is a chemical change you cant turn it back to what it was before. Its chemical properties have changed. Melting is a physical change. Its chemical properties are still the same it has not changed. It just changed it's physical form but the object is still the object.

altitude, density, pressure

air gets less dense the higher the altitude and also the air pressure is less as altitude rises.