7Fa Breaking Down

Bread contains starch, that is composed of ..........

• lime, lemons, and oranges.

• carbon, hydrogen, and oxygen.

• Pepsi, Coca Cola and Mountain Dew.

Hydrogen and Oxygen make up ...........

• an alkali.

• an acid.

• carbohydrate.

• water.

Frying an egg is ...........

• is a permanent change.

• is irreversible.

• is a chemical change.

• is all of the above.

Two liquids were mixed together in a glass. Which one of these would not show that a chemical reaction had taken place?

• The tube got warm.

• Bubbles of gas were given off.

• A brightly colored solid formed in the tube.

• One of the liquids floated on top of the other.

Which of these changes is a chemical reaction?

• melting some margarine in a pan.

• boiling a kettle of water.

• cooling a drink by placing an ice cube in it.

• baking a cake.

Physical changes are

• temporary.

• reversible.

• no new substances are made.

• all of the above.

Toasting bread is a ..........

• physical change.

• chemical change.

When bread is toasted. The ............. turns the bread black.

• carbon.

• hydrogen.

• water.

• oxygen.

How can you tell a chemical change has taken place in the decomposing banana?

• a gas is given off.

• a change in color.

• an energy change.

• none of the above.

One of the observations of mixing mentos with Coke is ...........

• a color change.

• gas is given off.

• none of the above.