Answer:
Option (1)
Explanation:
When two or more substances are chemically combined in a fixed proportion of mass, substance formed is a compound.
Properties of a compound are different from the properties of the elements from which the compound is formed.
If Magnesium (Mg) is burned in the presence of Oxygen (O₂), Magnesium oxide (MgO) is formed.
Properties of MgO are different from Mg and O₂ because MgO is a COMPOUND.
Option (1) will be the answer.
