Which of the following best represents and explains the formula for a compound made from fluorine and hydrogen?
hf, because both fluorine and hydrogen are capable of forming only one ionic bond.
hf, because both fluorine and hydrogen are capable of forming only one covalent bond.
h2f, because fluorine is short of two electrons, and hydrogen is short of one electron.
h2f, because fluorine is capable of forming one, and hydrogen is capable of forming two covalent bonds.

The answer to your question is: the second one.

Explanation:

HF, because both fluorine and hydrogen are capable of forming only one ionic bond.  H and F are nonmetals and can not form ionic bonds, so this answer is wrong.

HF, because both fluorine and hydrogen are capable of forming only one covalent bond.  This answer is correct, because these elements form only one covalent bond.

H2F, because fluorine is short of two electrons, and hydrogen is short of one electron.  This answer is incorrect because fluorine has seven electrons and hydrogen has only one valence electron.

H2F, because fluorine is capable of forming one, and hydrogen is capable of forming two covalent bonds. Both fluorine and hydrogen can form only one covalent bond, this answer is wrong.

Answer : The correct option is, HF, because both fluorine and hydrogen are capable of forming only one covalent bond.

Explanation :

Covalent compound : It is defined as the compound which is formed by the sharing of electrons between the atoms forming a compound.

The covalent compound are usually formed when two non-metals react.

Ionic compound : It is defined as the compound which is formed when electron gets transferred from one atom to another atom.

Ionic compound are usually formed when a metal reacts with a non-metal.

As we known that, hydrogen and fluorine are non-metals. So, they are capable of forming only one covalent bond.

Hence, the correct option is HF, because both fluorine and hydrogen are capable of forming only one covalent bond.