Every atom of the __ carbon has six protons

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?

Is this correct if not can u correct me

A0.100-kilogram apple hangs in a tree 1.50 meter above the ground. ignore frictional effects, the total mechanical energy of the apples is