How many atoms of carbon are contained in 0.203 mol of Al2(CO3)3

Drive down any three characteristic of modern periodic table

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?

Stage in which a typical star has completely stopped fusion