Draw "dot & cross" diagrams to show how different types of chemical bonds are formed when fluorine reacts with a) hydrogen, b) potassium.

In a dot and cross diagram you show the new positions of
the electrons after chemical bonding as taken place between two elements.  In covalent
bonding the electrons are shared therefore the atoms will overlap one another to show
the sharing of the electrons.  In iconic bonding the electrons are transferred so the
the atoms will be next to one another to demonstrate the electrons transfer to the other
atom.

The bond between hydrogen and fluorine to make
hydrogen fluoride is covalent as it is a bond between two
non-metals.

The bond between potassium and fluorine to make
potassium fluorine is iconic as it is a bond between a metal (potassium), and a
non-metal (fluorine).

As I am unable to post images here, I
have provided links in the sources below to the two diagrams for Hydrogen fluoride, and
Potassium fluoride that already exist on the internet.