(5 simple questions)
1. which of these is an indication that a chemical reaction has occured?
a. formation 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
b. new 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)