Consider this reaction:
Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g).
Which change could decrease the rate of production of ZnCl2?

first one is the correct answer

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements

under a microscope, cancer cells may look very different from normal cells. they often have different sizes and some may be larger than normal while others are smaller. cancer cells are often abnormally shaped and the control centre of the cell (the nucleus) may have an abnormal appearance.

i think? ?

they are all solids.