Periodic table 21, 22, 23, and 24 make an accurate comparis

When the earth was formed and cooled, why did nickel and iron end up in the center of the earth while basalt and granite ended up in the outer layers

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

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.