An element with the valence electron configuration 4s1 would form a monatomic ion with a charge . in order to form this ion, the element will (lose/ electron(s) from/into the (s).
if an element with the valence configuration 4s23d6 loses 3 electron(s), these electron(s) would be removed from the subshell(s).

+1, lose, 1, 4s, 4s and 3d

Explanation:

An element with the valence electron configuration 4s¹ would form a monatomic ion with a charge of +1. In order to form this ion, the element will lose 1 electron from the 4s subshell.

The corresponding oxidation reaction is:

K ⇒ K¹⁺ + 1 e⁻

[Ar] 4s¹ ⇒ [Ar]

If an element with the valence configuration 4s² 3d⁶ loses 3 electrons, these electrons would be removed from the 4s and 3d subshell(s).

The corresponding oxidation reaction is:

Fe ⇒ Fe³⁺ + 3 e⁻

[Ar] 4s² 3d⁶ ⇒ [Ar] 4s⁰ 3d⁵

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.