Which of these is an indication that a chemical reaction has occurred? a. freezing of a substance b. boiling of a substance c. melting of a substance d. a change in color of a substance

Choose all the answers that apply. as ocean depth increases, temperature decreases temperature increases pressure increases pressure decreases salinity increases density increases

The characteristic of two different types of reactions are shown below. reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of and element. which statement is true about the atoms of the elements that participate in the two reactions? a: their identity changes in both reaction a and b. b: their identity changes in reaction a but not b. c: their identity changes in reaction b but not a. d: their identity remains the same.

Which part of earth’s surface receives the most direct rays from the sun? a) equator b) ocean c) poles d) mountains