Predict where the largest jump between successive ionization energies occurs for Rb. 1. between the third and fourth ionization energies

2. between the second and third ionization energies

3. between the first and second ionization energies

4. between the fourth and fifth ionization energies

it would be between the first and second ionization energies

Explanation:

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.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.