GENERAL KNOWLEDGE

Detailed explanation-1: -Metals react with water to form oxides or hydroxides and release Hydrogen gas.

Detailed explanation-2: -A reaction of a substance with water is an example of a chemical property. Chemical properties are properties that can be determined when there is a change in the molecular structure of a substance. A chemical reaction will generate a new compound and thus the identity of the substance will be changed.

Detailed explanation-3: -Physical changes that involve a change of state are all reversible. Other changes of state include vaporization (liquid to gas), freezing (liquid to solid), and condensation (gas to liquid). Dissolving is also a reversible physical change.

Detailed explanation-4: -Since reacting involves the identity of the reactants getting changed and chemical bonds breaking and forming, reacting is a chemical process. Therefore, the reactivity of a substance is a chemical property that is about the chemical change that the substance can undergo when reacting.