I’m confused with this whole thing?

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

What will most likely happen when two bromine atoms bond together?

What is the molar mass of potassium nitrate, kno3