How many reactants are in copper

In a closed or isolated system , matter can not be created or destroyed. it can change forms but is conserved true or false

Evaluate this exponential expression,8. (2 + 3)2 – 42

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.