I need help on this one

This is a characteristic of the elements in the periodic table that shows a pattern. it may increase or decrease across or down the table.

Will mark brainliest how many electrons can be held in the energy level n = 4?

Why does earth rotate? because earth is formed from cold gases collapsing due to gravity because the matter in the nebula that formed earth was spinning because earth forms more than 99% of the mass of the solar system because the hydrogen atoms inside the nebula fused to form helium