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6th Grade Science / Lesson 2 - Floating


What will we be learning today?

  • In this lesson, we are going to learn all about what things float on others.

  • What Things Float on Others?

    Why does oil float on water? Does it have to do with measurements you can make? The photograph shows two identical beakers sitting on a balance. One contains 50 mL of water, the other 50 mL of corn oil. Both samples take up the same amount of space. However, the water has more mass, because the balance tips down on its side. Why does this happen?

    Both beakers contain the same volume of liquid, but the masses of the liquids are different. Does the water or corn oil have the greater mass?

    The water has more mass than the corn oil does. The amount of mass in a given amount of space is the density of an object.

    You can find the density of an object by

    finding the mass,
    finding the volume,
    and dividing the mass by the volume.

    When an object is placed in a less dense liquid or gas, the object will sink toward the bottom. If the liquid or gas is more dense, the object will float toward the top. If the object has the same density as the liquid or gas, it will "hover" in place.
    When this student releases the table tennis ball she is holding, it will rise to the top, like the other one. Table tennis balls have a lower density than water, so they float.

    Now you know that the liquids arranged themselves in order of density-the less dense liquid floats on the more dense, if the two liquids do not mix together.

    Let's Review What We Learned Today!

  • Now watch movie!

  • Then complete worksheet!