Check all that apply.
a. the electron configuration of o2− is [he]2s22p6.
b. the electron configuration of ag+ is [kr]5s14d9.
c. the electron configuration of ni is [ar]4s23d8.
d. the electron configuration of k is [ar]4s03d1.
e. the electron configuration of si is [ne]3s23p2.

options a, c, d and e

a. The electron configuration of O2− is [He]2s2 2p6.

c. The electron configuration of Ni is [Ar]4s2 3d8.

d. The electron configuration of K is [Ar]4s0 3d1.

e. The electron configuration of Si is [Ne]3s2 3p2.

Explanation:

A) The electronic configuration of Oxygen (O2) = [He] 2s2 2p4. On receiving TWO electrons, it becomes O2- with a new electronic configuration of [He] 2s2 2p6.

C) The electronic configuration of NICKEL (Ni) = [Ar], 3d8, 4s2.

Atomic Number of Nickel (Ni ) = 28. Electronic configuration in full is 1s2, 2s2, 2p6, 3s2 3p6 3d8, 4s2

D) The electronic configuration of Potassium (K) = [Ar] 4s1.

Atomic number of K = 19.

Electronic configuration in full is 1s2, 2s2, 2p6, 3s2 3p6 4s1.

E) The electron configuration of Si = [Ne] 3s23p2. Atomic number of Si = 14.

Electronic configuration in full is 1s2, 2s2, 2p6, 3s2 3p2

NOTE:

Atomic number of Silver (Ag) = 47.

Its electronic configuration is [Kr] 4d10 5s1.

On giving out ONE electron, it becomes Ag+ with [Kr] 4d10. Thus, ONLY Option b is INCORRECT.