Technically speaking, yes you can. Using a microscope though.
The statement is False.
The molecular (chemical) formulas are same in case of isomers but the arrangement of atoms is different in them. The physical properties are determined by the arrangement of atoms within the molecule.
Since the arrangement of atoms is different in case of isomers, the Physical Properties will also be different.
There is a couple different ways to determine if a bond is ionic orcovalent. By definition, an ionicbond is between a metal and a nonmetal, and a covalent bond is between 2 nonmetals. So you usually just look at the periodic table and determine whether your compound is made of a metal/nonmetal or is just 2 nonmetals.