What happens when a catalyst is used in a chemical reaction

Agas can holds 2.0 gal of gasoline. what is this quantity in cubic centimeters?

How many moles of carbon dioxide will form if 2.5 moles of c3h8 is burned

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?