Activity+2

Activity #2: Experimenting with Physical Changes


 * Materials**: salt, water, 50 mL beaker, hot plate, stirring rod

__**Procedure**__: Place one spoonfull of salt in a beaker. Add 30 mL of water. Stir until all of the salt is dissolved. Place the beaker on a hot plate. With the hot plate on low heat, leave the beaker on the hot plate for about 10 minutes or until all the water has left the beaker. Remove the beaker from the heat source carefully and as soon as the water is gone. DO NOT TOUCH the beaker with your hands - it is HOT! What is left in the beaker?

-The salt is left in the beaker because the water evaporated and the amount of salt we started with is left. Water- H2O Salt-NaCl
 * __Analysis__**: Write the chemical formula for water and salt.


 * __What evidence confirms that a physical changes has taken place?__**

When we started we had water and salt. We put the salt in the water and boiled it. When you boil the salt water that is a physical change. The water evaporated when it reached the boiling point. Then the salt was left in the beaker as it was when it was first put in. Since the salt water boiled there was a physical change.