Will mark brainliest! Topic is redox reactions, please follow the insturctions given above to help

Iknow #2 is d. i just need to know why

Identify one disadvantage to each of the following models of electron configuration: dot structures arrow and line diagrams written electron configurations type in your answer below.

An atom's configuration based on its number of electrons ends at 3p4. another atom has seven more electrons. starting at 3p, what is the remaining configuration? 3p63d34s2 3p43d54s2 3p64s23d3 3p44s23d