Density+and+buoyancy-+Phase+Changes

Density and Buoyancy-

NNC has used many resources from [|middle school science]

Use density to find out why diet Coke floats and Coke sinks- get kids to read the ingredients and then mass out the amount of sugar listed on the nutrition facts.

Compare fun sized snickers and three musketeers to see which sinks and floats and why.

Compare old and new pennies- what year did the composition of pennies change?

Have a competition to make foil boats out of 60 cm aluminum foil and see how many weights or pennies they can hold before they sink.

Dave Zemek's Jolly Rancher lab-

Density column- in CPO

Practice with mass and volume-

Make Lava lamps from water bottles with colored water and oil- try to find objects with a density greater than water and less than oil to float in the middle

Cartesian divers are fun there are many online variations- for example [|Cartesian diver]

Show the class used motor oil- will it float or sink? They will likely predict sink and be surprised when it floats.

Drop an ice cube in alcohol and water, Can they explain why the ice cube sinks in alcohol in terms of density

From Dave-Z- To show gas density fill a graduated cylinder with propane (ie from a plumbers torch or BBQ tank)and pour it into a beaker in front of a strong light or projector- The gas will be invisible, but will cast a shadow on the screen- very cool!


 * Phase Changes-**

Here is the lesson that the 10/3/12 DAIT team put together along with the flow map for the writing and the concept map for this unit Dave Z's "This Lab Sucks" Crush the can

Dry ice is a great way to show sublimation put some in a balloon or rubber glove to demo sublimation (use caution)- also difference between solid and gas. Use gloves and goggles! Dry ice can also be used to show that gas has mass and how different the volume is between these two states.

For demos, use this form to get kids thinking about what is going on at the nano scale and how to visualize it:

Use kids to act out or dance states of matter. Metal ball and ring demo. –thermal expansion. Put a balloon on a flask and heat and cool the flask to watch the balloon shrink and expand.

Put a penny on top of a 4 oz glass bottle and hold it in your hand to heat- the penny will burp as it lets the expanding air out.

Dave- hero’s steam engine <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Graph the temperature change as a beaker of ice on a hot plate goes from solid, to liquid, to boiling. pg 97 in the student text <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Lots of great gaggle videos on phase changes including "Honors Chemistry Phase Changes Lecture" <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Bill Nye- Phases of matter on United Streaming

<span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">CPO Lab 5B <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">CPO lab 5A- as a demo or this can be modified by challenging students to use a balloon and a balance to find the mass and density of air

<span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;"> Have students make silly putty on page 112 (student text) and try to decide if it is solid or liquid. They can read 110 and 111 to understand the answer.

<span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Mythbusters "walking on water" for a mass oobleck demo- is it a solid or a liquid? <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">A three way venn diagram from Steve Fry for the three phases- you could also make a "triple bubble" with the same content. a double bubble of just gas and liquid can also be made.

<span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Connect pressure to the 7th grade blood pressure lab. <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Show a blown out soda can with both ends bulging out and ask what could have happened to elicit prior knoweledge. <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Have kids make lots of drawings of what they visualize at the nano scale. <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">model states with beads in a petri dish under the document camera <span style="background-color: transparent; color: #000000; font-family: serif; font-size: 16px; text-align: start; text-decoration: none; vertical-align: baseline;">Use the diagram dialougue to understand visual representations of phase changes like the visual o page 94