The first ionization energy (kilojoules per mole) for each group 1 element are shown.

Question

Group 1 elements.Short description, Group 1 elements.,Long description,
The following elements are included:

Element Symbol

Atomic Number

First ionization energy in kilojoules per mole

Li

3

520

Na

11

496

K

19

419

Rb

37

403

Cs

55

376

Question
Which statement explains the trend in first ionization energy of group 1 elements?

Answer options with 4 options
A.
As the number of valence electrons increases, the amount of energy required to add an electron to the atom decreases.

B.
As the number of valence electrons increases, the amount of energy required to remove an electron from the atom decreases.

C.
As the distance between the nucleus and the outermost electrons increases, the amount of energy required to add an electron to the atom decreases.

D.
As the distance between the nucleus and the outermost electrons increases, the amount of energy required to remove an electron from the atom decreases.

Answer 1

B. As the number of valence electrons increases, the amount of energy required to remove an electron from the atom decreases.