| A | B |
|---|
| The basic unit of all elements | atom |
| The center of the atom | nucleus |
| Inside the nucleus are positively charged particles | protons |
| Around (outside)the nucleus are particles of a negative charge | electrons |
| These are inside the nucleus with the protons and have a nuetral charge | neutrons |
| Frost action, plants growong underneath rocks and pressure unloading are examples of | physical weathering |
| Alternate freezing and melting of water | frost action |
| The reaction of carbonic acid with other substances | carbonation |
| The processes that produce changes in the surface of rocks exposed to the atmosphere | weathering |
| Temperature and humidity can describe a | climate |
