1. Which of the following electron configurations represents an element in an excited state?

A. 1s²2s²2p⁵
B. 1s²2s²2p⁶3s²3p⁶4s²3d⁸
C. 1s²2s²2p⁶3s²3p⁶4s¹3d⁵
D. 1s²2s²2p⁶3s²3p⁶4s²3d⁵
E. 1s²2s²2p⁶3s²3p²4s¹

2. How many unpaired electrons are present in the +2 cobalt ion, Co²⁺, in its ground state?

A. 2
B. 3
C. 4
D. 5
E. 6

3. Please indicate which element corresponds to each of the following electron configurations.

A. 1s²2s²2p⁶
B. 1s²2s²2p⁵
C. [Kr]5s¹4d⁵
D. [Ar]4s²3d¹⁰4p⁴

4. Why is each of the following electron configurations incorrect for atoms in their ground states? How could you correct each of these?

A. 1s²2s²3s²
B. [Ar]3s²3p³
C. [Ar]4s²4d³

5. Please write the electron configuration of each of the following elements:

A. Oxygen
B. Potassium
C. Arsenic
D. Manganese
E. Copper

6. Please write the condensed electron configuration of each of the following elements:

A. Fr
B. Br
C. Ca
D. Zn