Question

1. barium

a cs
b la
c rn
d xe

Explanation:

Barium (Ba) has an atomic number of 56. The electron configuration of Barium can be determined by looking at the noble gas that precedes it in the periodic table. Xenon (Xe) has an atomic number of 54, so the electron configuration of Barium is \([Xe] 6s^2\). So the correct noble gas core for Barium is \([Xe]\).

Answer:

D. [Xe]