Which of these is an example of a chemical reaction that occurs at a very slow rate

a. alcohol burning
b. an explosion
c. dissolving an antacid tablet
d. iron rusting

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

Acontrol during an experiment. might change remains constant does not exist does change

Helium decays to form lithium. which equation correctly describes this decay?