Sagot :
(4) Isomers have the same molecular formula (same number of each type of atom) but have a different
structure.
Answer: (4) molecular formula
Explanation:-
1. Density of a substance is defined as the mass contained per unit volume.
2. Melting point is the temperature at which solid start changing to liquid phase.
3. Reactivity of an element is defined as the ability to lose or gain electrons.
4. The compounds having similar molecular formula but different arrangement of atoms or groups in space are called isomers.
[tex]CH_3OCH_3[/tex] and [tex]CH_3CH_2OH[/tex] are functional isomers which have same molecular formula but different functional groups namely ether and alcohol respectively.