Editing Density Rainbow (section)

== Demonstration ==

===Method A===
# Set the graduated cylinder on a table with a bin or tablecloth underneath to catch any spills. Add 100 mL of water to the cylinder before the start of the event.
# Let students add one of the other liquids in (but only a small amount) and watch where it ends up. Is it above or below the water? As more liquids are added, they will sort themselves by density, and students will be able to see some clear distinctions between the liquids!
# Let students know that the density of something is equal to its mass divided by the volume it takes up. Give them a small object and ask them to predict where it will float in the cylinder before dropping it in. Was their prediction correct?

===Method B===
# Measure out 100 mL of water into each of the small beakers. Add three drops of food coloring to four of the beakers, with each getting only one of the colors.
# Add sugar to each of the colored beakers. Give two teaspoons to red, five to yellow, eight to green, and eleven to blue. Mix each one thoroughly, rinsing or wiping the spoon between beakers so that a beaker doesn't get too much or too little sugar.
# In the big beaker, first add the blue solution. Then, to add the rest of the solutions in color order, ending with clear, by pouring them slowly over the back of the spoon to prevent splashing and mixing. If done correctly, the solutions will stack on each other, creating a rainbow!

===Method C===
# Measure out 100 mL of water in each of the beakers. Start heating one on the hot plate, and add ice to another and let it cool down.
# Add 2 drops of food dye to each of the beakers; red in the hot beaker, green in the room temperature beaker, and blue in the cold beaker.
# Once the hot beaker is hot, turn off the heat plate. Add the blue water to the large beaker first. Then add the green water, pouring it over the back of a spoon to ensure it spreads out and doesn't mix much. Repeat for the red water, and if done correctly the solutions should stay mostly separated!
# The solutions will mix over time as the temperatures become more balanced, so plan to reset this demonstration every 15 minutes or so.