Energy and Chemicals

Which of the following is an example of a chemical change?

• ice melting into water

• rust forming on a metal fence

• sugar dissolving in water

• breaking a glass into pieces

In the chemical formula H₂O, how many hydrogen atoms are there?

• 1

• 2

• 3

• 4

What is the solvent in a salt water solution?

• salt

• water

• both salt and water

• neither salt nor water

Which factor does NOT affect the rate of dissolution?

• temperature

• surface area

• color of the solution

• agitation

In an energy pyramid, what happens to the available energy at each trophic level?

• it increases

• it stays the same

• it decreases

• it multiplies

During a physical change...

• a new substance is formed

• chemical bonds are broken

• the molecular structure changes

• the appearance changes but the substance stays the same

How many oxygen atoms are in the formula Fe₂O₃

• 1

• 2

• 3

• 4

What is the concentration in an aqueous solution?

• the amount of water present

• the amount of solute dissolved in the solvent

• the temperature of the solution

• the color of the solution

Which would dissolve faster in water?

• a large sugar cube

• a sugar cube crushed into powder

• a frozen sugar cube

• a sugar cube that is cold

Which organisms are at the top of an energy pyramid?

• producers

• primary consumers

• secondary consumers

• tertiary consumers