Write equations that show the processes that describe the first, second, and third ionization energies for a gaseous gadolinium atom. Express your answers as chemical equations separated by commas. Identify all of the phases in your answer.

Gd(g) → , → , →

Explanation:

Ionization energy is the energy required to remove an electron from a gaseous atom or ion.

The first ionization energy is the energy required to remove the valence electron(outermost) from a neutral atom:

Gd(g)→

The second ionization energy is the energy required to remove next/second electron from ion. The second ionization energy is always higher than the first:

(g) →

The third ionization energy is the energy required to remove third electron from ion:

(g) →  

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.