Evidence of Chemical Reactions

What happens to water when it changes from a solid to a liquid?

• It becomes a different chemical.

• Its chemical structure changes.

• It remains H2O.

• It forms a new gas.

Which of the following is NOT an indicator of a chemical reaction?

• Change in shape

• Formation of a gas

• Temperature change

• Formation of a precipitate

What is a precipitate?

• A color change in a reaction

• A liquid that evaporates

• A solid formed in a solution

• A gas formed in a reaction

What does a color change in a reaction indicate?

• The reaction is complete

• The solution is diluted

• A new substance has formed

• The temperature has increased

What does a temperature change in a reaction signify?

• Energy has been absorbed or released

• The reaction is reversible

• A new gas is formed

• The reaction is slowing down