Oct. 26 & 27Welcome Assignment

• Extra Credit Word Search and Sudoku will not be accepted. The assignment is closed.• Please take out your take home test and pass it forward. • Take out a sheet of paper

– Write name, period, and date– Title: Convection Currents/Density and our Ocean – Lab Activity

Convection Current/Density in our Ocean Lab Activity

• Research Question/Purpose: How do convection and density affect our ocean waters? How does the salinity of the water affect the current?

• Background information: – Convection = transfer of heat by a fluid (liquid

or gas)– Density = the amount of matter in a given

space. mass/volume

Materials

• 8 ice cubes (2 each trial)• Fresh warm water• Beaker tongs• A ruler• Thermometer• 250ml beaker• Salt (about 70 grams)• Spoon• Paper towels• Timer

Procedure

1. Obtain an ice cube that has been strongly dyed with food coloring

2. Using the beaker tongs, gently place the ice cube in a beaker ¾ full of warm, fresh water. Keep the beaker and water as still as possible.

3. Observe the ice – water mixture for 5 minutes. Write a detailed description of your observations

4. Measure the temperature at the surface, at the bottom of the mixture, and 3 measured levels in between.

Procedures continued…

5. Empty the beaker and fill it to the same level with warm water.

6. Add salt to the water, stirring vigorously as you pour until no more salt will dissolve (saturated solution)

7. Repeat steps 3 and 4 using salt water in place of fresh water (do 2 trials of fresh water and 2 trails of salt water, first set for observations, second for temperature)

Trial 1 Fresh water Trial 2 Fresh water

Trial 3 Salty water Trial 4 Salty water

Data/ObservationsMin Observations Fresh H2O

1

2

3

4

5

Depth Temp of Fresh H20

Surface

½

Bottom

Min Observations Salty H20

1

2

3

4

5

Depth Temp of Salty H20

Surface

1/2

Bottom

November 2 & 3Homework Tonight

• TeenBiz3000 – 4 articles due Nov. 30th

– No Water– A new way to study the ocean– Walking on thin ice– What is happening under the earth

• Data analysis and Conclusion for Lab

Data Analysis

• Looking at the data, compare them. How does the Saltwater data differ from the Fresh water data? How are they the same? (you can draw a double bubble map)

Conclusion

• What errors may have hurt your results?• How did the salt change the results? And

Why?• How might this saltwater model be an

example of the ocean currents?• How do convection and density affect our

ocean waters? • How does the salinity of the water affect

the current?