What is mean by the term event dating.

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

Joan writes four numbers on the board in standard form, and then she writes their scientific notation

Ascientist is measuring the pressure that is exerted by each of the following gases in the atmosphere: carbon dioxide, oxygen, and nitrogen. which term most likely describes what she is measuring?