What is a chemical reaction?
A process in which substances change and form new substances.
Which situation shows a chemical change?
A. Cutting paper
B. Melting ice
C. Burning paper
D. Breaking a pencil
C. Burning paper
Which of the following is evidence that a chemical reaction may have occurred?
A. Change in color
B. Formation of gas
C. Formation of a precipitate
D. All of the above
D. All of the above
What type of chemical reaction occurs when one substance breaks down into two or more simpler substances?
Decomposition
What type of chemical reaction occurs when an acid reacts with a carbonate and produces a gas?
Acid on carbonates
What gas is commonly produced when an acid reacts with a carbonate?
Carbon dioxide
What type of chemical reaction occurs when a substance reacts with oxygen and releases heat and light?
Combustion
What type of chemical reaction occurs when an acid reacts with a metal and produces hydrogen gas?
Acid on metals
What gas is commonly produced when an acid reacts with a metal?
Hydrogen
What type of chemical reaction happens when paper, wood, or fuel burns?
Combustion