(5 simple questions)

1. which of these is an indication that a chemical reaction has occured?
   

Aformation of gas

b.freezing of a substance

c.boiling of a substance

d.melting of a substance


2.If the temperature changes in a chemical reaction, what has occurred?

a.energey was destroyed

b.energy was transferred

c.energy was created

d.there was no energy transfer






3.Which of these Accurately describes the reactants of a reaction?

a.substances that do not participate of a reaction

Bnew substances that are present at the end of a reaction

c.substances that are used up in a reaction

d.new substances formed in the reaction




(rest are below)