Density

Density 1 Which is heaviest, 1 kilogram of gold or 1 kilogram of feathers? 2 Which is bigger, 1 kilogram of gold or 1 kilogram of feather? 3 Basically, density is how compact an object is. 4 Density is the mass of an object divided by its volume. 5 Volume is the amount of space that something takes up. 6 Scales measure the pull of gravity on an object. 7 Balances compare the mass of an object to a known mass, so they read the same on the Earth and Moon. 8 Calculate by D = M/V

end................................................................................................................ Explain Voice higher and lower Myth Busters https://www.youtube.com/watch?v=A4hUNOpyeFY

[|Density Explained]

Density Simulation [|Turn a ball bearing into a ping pong ball] [|Rainbow Straw.].(Looks fun/Needs clear straws) List of Densities Zinc vs. Copper Penny Density Identifying Fakes by Density

Exploring the Depths - Inquiry density lab using different densities of saltwater. http://www.iacad.org/istj/37/2/density.pdf

Prepare five solutions of colored saltwater in two-liter bottles. Add 1 cup of table salt to one bottle, ¾ of a cup to the second bottle, ½ cup to the third bottle, and no salt in the last bottle. Also prepare an “unknown” solution containing ¼ cup of salt. Add food coloring to teach bottle, noting the color of each solution for future reference. Label each bottle do not drink to model safety. One test tube per student, cups and droppers.

Here are four solutions of saltwater each with a different density. What are some ways that we can compare the densities of these solutions? Have student ideas recorded and displayed. How could this be done without using a balance? Wait time and look at each student? Generalize the list and discuss pros and cons.

Have pairs develop a specific procedure. Ask what problems might you encounter with your procedure. How can mixing be minimized?

Once procedures are approved students can test them. Students should record their observations for each test. Students must give physical, written, and verbal evidence for their conclusions regarding the relative densities.

What do you conclude about the densities of the solutions? How does you data support your conclusion? Hoe does the fact that I did not tell you if you were correct relate to the way scientists gain confidence in their ideas? If there are different conclusions, how might the correct answer be found? What does comparing conclusion do to the confidence we have in our results? Why is it important that scientist don't vote on their ideas?

These observations are qualitative. How might we get quantitative observations? Balances and graduated cylinders are then employed. How many time do you think you need to do each measurement in order to be confident in your results? Record the data to use during the challenge.

Compile student densities for each solution. How consistent is you data? Which experimental values are the farthest from the pattern you infer? How do you explain the data farthest from the pattern? Taking all the data into account, what do you think the actual density of the solution is.

Challenge students to find the density of the unknown saltwater solution without making quantitative measurements. How can you estimate the density of the unknown solution.

Have students check their estimated density using quantitative methods.

Oil, water, color, bubbles. http://www.sciencebob.com/experiments/lavalamp.php

Divers Test tube ketchup pack http://www.sciencebob.com/experiments/magic_ketchup.php