Which of the following is not an indicator of a chemical change?

color change
change in volume
temperature changes
gas formation

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

Why must humans find substitutes for many minerals found on earth? (a) form at an extremely slow rate (b) controlled by other countries (c) too deep in the earth to collect

Astream of surface water reaches a porous portion of sediment and seeps into the ground. this water eventually joins a large reservoir of water located beneath the earth's surface. the example above describes the interacting with the a. cryosphere; biosphere b. hydrosphere; biosphere c. hydrosphere; geosphere d. cryosphere; geosphere