Answer
The correct statements are:
A. Elements are rarely in their pure form.
D. A chemical bond is a strong attractive force between atoms.
Step-by-step explanation
Few elements can exist in their natural pure form, but many elements don't exist in their pure form in nature due to their chemical or atomic instability.
And because noble gases are reluctant to share electrons from their filled outer electron shells, noble gases are generally considered unreactive.
A full valence shell is the most stable electron configuration that has two (duplet) or eight (octet) valence electrons.
A chemical bond is a strong attractive force between atoms, ions or molecules that enables the formation of chemical compounds. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds.
Therefore the correct statements are:
A. Elements are rarely in their pure form.
D. A chemical bond is a strong attractive force between atoms.