Need Help please! Label the acid, base, conjugate acid, and conjugate base in the following reaction

H2PO4'(aq)+Br(aq)<—> HPO42(aq) +HBr(aq)

Thank you!

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.