Question 1(multiple choice worth 4 points)

during a chemical reaction, what remains constant?

composition
temperature in beaker
amount of energy
the bonds

question 2(multiple choice worth 4 points)

(sc.912.p.8.2)

which of the following is not a physical change?

freezing ice
molding clay
filtering a mixture
cooking a steak

question 3(multiple choice worth 4 points)

the type of change where new compounds are formed is called a

chemical change
phase change
physical change
nuclear change

question 4(multiple choice worth 4 points)

(sc.8.p.9.1)

where does the energy given off by an exothermic reaction come from?

the chemicals make the energy during the reaction from atoms that are consumed.
the atoms in the air are converted to energy during the explosion.
the energy is converted from the heat taken in by the exothermic reaction.
more energy is given off by the new bonds formed than is needed to break the original bonds.

question 5(multiple choice worth 4 points)

when 10 grams of salt dissolve in 25 grams of water, what is the resulting mass of the mixture?

the resulting mass would be 15 grams.
the resulting mass would be 35 grams.
the resulting mass would be 40 grams.
the mixture would need to be measured to determine the mass.