A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion. B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion. C. If Assertion is true statement but Reason is false. D. If Assertion is false and Reason is true i Assertion: .Burning of magnesium ribbon produce whitish powder called magnesium oxide. Reason : Magnesium is generally cleaned by rubbing it on sand paper

C. If Assertion is true statement but Reason is false.

Explanation:

The burning of magnesium in air produces magnesium oxide as shown by the equation;

2Mg(s) + O2(g) > 2MgO(s)

The magnesium oxide solid is recovered as a white ash. This is a typical example of an oxidation reaction which is also a combustion reaction.

The reason has nothing at all to do with the assertion hence the answer given.

Magnesium oxide is basic just like the oxides of other metals and dissolves in water to yield an alkali.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements