CHM1025C Module One: Sample Exam Homework  ANSWERS

                  

Part D: Chemical/Physical/Nuclear Change   5 points

State whether each of the following is a physical change,  a chemical change, or a nuclear change:

 

___chemical ______1. Electricity decomposes water.

 

 

___ physical ______ 2. Methanol dissolves in gasoline

 

 

___ physical_______ 3. Dry ice pellets disappear

 

 

___ chemical _____ 4. Iron oxidizes to rust

 

 

___ physical  _____ 5. Bromine vaporizes into a reddish-brown gas

 

 

___ nuclear______ 6. Uranium-235 splits into two small elements when bombarded

                                         with neutrons in an atomic bomb.

 

___ physical ______7. Copper conducts heat

 

 

___ chemical _____8. Baking soda fizzes in vinegar

 

 

____ physical _____9. Grinding sugar crystals into a powder

 

 

____ chemical ____10. Sodium reacts with chlorine gas

 

 

____ physical _____11. Adding air to a tire

 

____ physical _____12. Slicing an orange into wedges

 

____ nuclear  _____13. Hydrogen atoms fuse into helium atoms in a hydrogen bomb

 

____ physical _____14.” Dry ice”(Solid Carbon dioxide) vaporizes (sublimes) into a

                                          gas at room temperature and sea level pressure

 

____ chemical ____15. Natural Gas burns with a blue flame