What is an enzyme? 1
A catalyst that breaks down
large molecules
2
A catalyst that speeds up a
reaction
3
A biological catalyst / substance
that speeds up chemical
reactions

9. write the chemical equation for the following word equations. include symbols for physical states in the equation. a. solid zinc sulfide + oxygen gas -> solid zinc oxide + sulfur dioxide gas b. aqueous hydrochloric acid + aqueous barium hydroxide -> aqueous barium chloride + water

The identities of substances are the same before and after which type of change

What must be in balance for temperatures to remain constant?