Question

rank the following atoms in order of increasing first ionization energies (i.e., lowest to highest): rb, f, mg, b, n
answer:
a f < n < b < mg < rb
b rb < mg < f < n < b
c mg < rb < f < n < b
d rb < mg < b < n < f

Explanation:

Step1: Recall ionization - energy trend

Ionization energy increases across a period and decreases down a group in the periodic table.

Step2: Locate the elements

Rb is in Group 1 and Period 5, Mg is in Group 2 and Period 3, B is in Group 13 and Period 2, N is in Group 15 and Period 2, F is in Group 17 and Period 2.

Step3: Analyze based on trends

Rb is the largest atom among them and has the lowest first - ionization energy as it is in the lowest period and left - most group among these elements. Mg is larger than B, N, and F but smaller than Rb. B, N, and F are in the same period, and among them, B has the lowest ionization energy in this period due to its electron - configuration, followed by N, and F has the highest ionization energy in this period.

Answer:

D. Rb < Mg < B < N < F