The answer for this would be 69.6
Answer:
20.0928.
Explanation:
The average atomic mass is (90 * 19.992 + 10* 21) / 100
= 20.0928.
Innovated Understanding Curious Logical
1s2 2s2 2p1
fifth electron is in 2p orbital
so answer is 2 2 -1 -1/2 , or 2 2 -1 1/2
*1/2 and -1/2 are spins, so they are interchangeable when writing the first electron in the ml