The bond between f and cl would be: pure covalent polar covalent ionic metallic

Polar Covalent

Explanation:

Chlorine and Fluorine are both halogens. They are in group VII.

The Pauling's electronegativity value of these elements are:

F = 4.0

Cl = 3.0

Electronegativity of an element is a property that combines the ability of its atom to lose and gain electrons. It can be used to predict bond type.

For heteronuclear molecules where the electronegativity difference is between 0.5 and 1.7 there will not be an equal sharing of the electron pair between the atoms involved.

The bond that results is a Polar Covalent bond.

When the electronegativity difference is zero or less than 0.5, a non-polar covalent bond forms. There would be an equal sharing of the electron pair donated.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.