Si hablamos de las capas M, N y O son los niveles
4,5,6
1,2,3
2,3,5
2,3,4
3,4,5

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

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Most materials are not magnetic because their magnetism has worn off. their magnetic domains are arranged randomly. they lack magnetic fields. earth’s heat has destroyed their magnetism.