What must occur for a change to be a chemical reaction

98 ! and brainliest plz ! the below reaction can be categorized as more than one type of reaction. which reactions are these, and what are the types of reactions?

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

Energy defines the different "states" of matter. in no more than 3 sentences, describe the amount of kinetic energy that each of the 3 states of matter possesses and relate that to the atom/molecular motion of each "state".