How many subshells are there in the n = 4 principal shell? how many subshells are there in the n = 4 principal shell? 1 2 3 4 not enough information?

At 450 mm hg a gas has a volume of 760 l, what is its volume at standard pressure

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?

The lewis diagrams for magnesium and fluorine are shown below. what is the correct chemical formula for magnesium fluoride? a. mgf b. mg2f c. mgf2 d. mg2f3