Answer is: 1) NaCl.
NaCl is sodium chloride, ionic compound.
Ionic compounds are made of ions held together with ionic bonds.
Ionic bond forms when a cation transfers its extra electron to an anion who needs it.
Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.
Δχ(Na-Cl) = 3.2 - 0.95 = 2.25; electronegativity difference between sodium and chlorine.
When the electronegativity difference is greater, the bond polarity is increasing.
Other compound have covalent polar bonds.
