How did changes brought about by the Great War lead to the boom of the 1920’s and the bust of the 1930’s?

Achemist determined by measurements that 0.0300 most of beryllium oxide participate in a chemical reaction calculate the mass of berlylium oxide that participates

How many liters of hydrogen gas will be produced at stp from the reaction of 7.179×10^23 atoms of magnesium with 54.219g of phosphoric acid (h3po4) the equation is 3mg + 2h3(> mg(po4)2+3h2

Which of the following electromagnetic waves can create ions?