What is the most effective way to differentiate between potassium feldspar and plagioclase feldspar?

Ineed with a, b, c, d, and e on the long answer

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?

Can someone solve thierry two problems