T3 Lesson 2 Quiz: Chemical Change

Liz is exploring the different kinds of changes that can happen to substances. Liz knows that changes can alter the looks or shape of a substance. Cutting, melting, bending, or crushing are examples of what kind of change?

• reactant
• product
• physical
• chemical

Liz is exploring the different kinds of changes that can happen to substances. After reading about the kinds of changes that occur, Liz saw some rust on a pipe that was going into her house. What kind of change is the formation of rust?

• reactant
• product
• physical
• chemical

After learning about chemical reactions, Olivia investigated different kinds of chemical changes using substances she found in her kitchen so she could see these changes. Which of the following can occur when a chemical reaction takes place? Choose the THREE statements that apply.

• New bonds form.
• Existing bonds break.
• New substances form.
• Changes don’t affect matter.

In a chemical change, atoms and molecules rearrange to form new ones. Substances that undergo chemical changes are called __________________________.

• reactants
• products

In a chemical change, atoms and molecules rearrange to form new ones. What these atoms & molecules form are called _________________________.

• reactants
• products

Kim understands that there are several signs that indicate a chemical reaction has occurred. What is the best way to be certain that a chemical reaction has occurred?

• Some bubbles form.
• A color change occurs.
• A new substance forms.
• The materials do not react.

Some chemical reactions need energy in the form of heat to take place, while others give off energy. The temperature after Reaction 1 takes place is _______________ the temperature before the reaction which means this graph represents a ________________ reaction.

• greater than; endothermic
• greater than; exothermic
• less than; exothermic
• less than; endothermic

Some chemical reactions need energy in the form of heat to take place, while others give off energy. Reaction 2 requires an endless source of energy. The temperature after the reaction is _________________ the temperature before the reaction which means Reaction 2 is an ____________________ reaction.

• greater than; endothermic
• greater than; exothermic
• less than; endothermic
• less than; exothermic

Dax has been learning about chemical reactions, and he now understands that chemical reactions occur at different rates. Some are very fast, while others are quite slow. Depending on the conditions, a particular reaction can happen at different rates. Which condition(s) can affect the rate of a chemical reaction?

• surface area
• temperature
• concentration
• catalysts/inhibitors
• all of the answer choices affect the rate of a reaction

The minimum amount of energy needed to start a chemical reaction is called ___________________________.

• activation energy
• solar energy
• chemical energy
• catalyst energy