How many moles of MgBr2 would you have if you had 7.0 grams of magnesium bromide?

Most smaller stars don't have a radiative zone.

If a hydrogen atom is neutral, it must also have  one electron. an oxygen atom (o) has an atomic number of eight (8). this means a neutral oxygen atom has eight protons and eight electrons. the element actium (ac) has an atomic number of 89, so it has 89 protons and 89 electrons in a neutral atom