1. Freezing/Melting and Boiling Points

2. Spacing of Molecules in a Solid, Liquid, & Gas
Use this link

3. Freezing/Melting Point
What is freezing point?
It is the temperature at which a liquid becomes a solid
rain
cools
snow

4. Freezing/Melting Point
What is melting point?
It is the temperature at which a solid becomes a liquid
snow
warms
rain

5. Freezing/Melting Point
What is the unit of measurement that scientists use for temperature?
Celsius
What is the temperature at which a WATER (liquid) becomes a solid (ice or snow)?

6. Freezing/Melting Point
What is the temperature at which a WATER (liquid) becomes a solid (ice or snow)?
0o degrees Celsius

7. Freezing/Melting Point
If the temperature warms up 1 degree above 0o Celsius – what happens?
The ice or snow will melt
Or change from a solid to a liquid

8. Water is a liquid that changes to a solid when it freezes.
Freezing Point
Water freezes at ____ degrees Celsius
On your handout, use a marker to color in the temperature at which water freezes or becomes a solid (ice or snow) on the “Freezing Point” thermometer
Water is a liquid that changes to a solid when it freezes.

9. Boiling Point What is a boiling point?
It is the temperature at which a liquid becomes a gas.
Gas

10. Boiling Point What is the boiling point of water?
Does water continue to get hotter the longer you let it boil?
Let’s try it & see

11. Boiling Point At what temperature did the water boil? 100o Celsius
Did the water continue to get hotter the longer you let it boil? No
Once the water boils, it will not get any hotter – it will continue to boil until it all the liquid changes into a gas

12. Water is a liquid that changes to a gas when it boils.
Boiling Point
100
Water boils at ____ degrees Celsius
On your handout, use a marker to color in the temperature at which water (a liquid) boils or becomes a gas on the “Boiling Point” thermometer
Water is a liquid that changes to a gas when it boils.

13. Heating Chocolate What happens to chocolate when we heat it?
Is the chocolate chip a solid or liquid?
It’s a solid
Place one chip on your spoon and hold it over the candle for about 45 seconds
Use your tooth pick to poke it

14. Heating Chocolate What happens to chocolate when we heat it?
Is the chocolate chip a solid or liquid AFTER heating?
It’s turning into a liquid
Did it boil or change into a gas? NO
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15. Does it change into a gas?
Yep!
Yep!
Yep!

16. Water boils at 100o C