Chemical Reactions

When a new substance forms as a result of a chemical reaction, what type of change has occurred?

• Chemical Change

• Physical Change

What is the left part of a chemical equation called?

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

What is the right part of a chemical equation called...

2H_{2 +} O₂ --> 2H₂O

• Reactants

• Yields

• Products

• Chemical Equation

True or False

In a chemical reaction, no new atoms are created, and no atoms are destroyed.

• TRUE

• FALSE

Which statement is not a description of a chemical reaction?

• A solid is dropped into a beaker of liquid and a gas is released.

• A solid is dropped into a beaker of liquid and an explosion occurs.

• Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker.

• A liquid is heated in the sun and half of it evaporates.

In a chemical reaction

• The atoms of the reactants always stay together to form the products
• The atoms of the reactants unbond, rearrange, and then rebond to form the products
• New atoms are formed which combine to make the products
• Some atoms disappear while others multiply to form the products

Which observation(s) might be used as evidence that a chemical reaction occurred?

• Color change

• Odor change

• change in temperature

• All of the above

_________ is (are) made of more than one atom.

• A molecule
• Protons
• Neutrons
• An element

________ result(s) in no new substances.

• A physical change
• A chemical change
• Physical and chemical changes
• None of the above

Which is an example of a physical change?

• Burning wood
• Freezing water
• Rust on a car
• Cooking food