What best explains the formula unit for a compound made from fluorine and hydrogen? 1. HF, because fluorine is short of one electron, and hydrogen is in excess of one electron
2. HF, because both fluorine and hydrogen are capable of forming only one covalent bone
3. H2F, because fluorine is short of two electrons, and hydrogen is short of one electron
4. H2F, because fluorine is capable of forming one, and hydrogen is capable of forming two covalent bonds

2)HF bcz both fluorine and hydrogen are capable of forming only one covalent bond

Explanation:

flourine is short one electron to become stable while hydrogen has only one electron.Hydrogen cant give out its one electron fully thus it will share its one electron with flourine

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.