Hydrochloric acid reacts with calcium carbonate to produce calcium chloride, liquid water and carbon dioxide gas. If 2.5 g of gas is produced when 4.50 g hydrochloric acid is allowed to react with 15.00 g calcium carbonate, what is the percent yield of this reaction?

The mass has escaped into a gas which you can not see so the law stays true.

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts