Question

consider the set of successive ionization energies.
ie₁ = 589.8 kj/mol
ie₂ = 1145.4 kj/mol
ie₃ = 4912.4 kj/mol
ie₄ = 6491 kj/mol
identify the element in period 4 that corresponds to this set of ionization energies.
ga
ca
ge
k

Explanation:

Step1: Analyze ionization energy jumps

Ionization energy ($IE$) is the energy required to remove an electron from an atom. A large jump in $IE$ indicates that a core electron is being removed. For the given values, there is a large jump between $IE_{2}$ and $IE_{3}$. This implies that after removing 2 valence electrons, the next electron is from a lower - energy shell (core electron).

Step2: Determine valence electron count

Elements with 2 valence electrons in period 4:

• $K$ (potassium) has 1 valence electron ($4s^{1}$).
• $Ca$ (calcium) has 2 valence electrons ($4s^{2}$).
• $Ga$ (gallium) has 3 valence electrons ($4s^{2}4p^{1}$).
• $Ge$ (germanium) has 4 valence electrons ($4s^{2}4p^{2}$).

Since there is a large jump after removing 2 electrons, the element has 2 valence electrons.

Answer:

Ca