Learn why an object float or sink.

1. WHAT FLOAT? WHAT SINK?
Cam-Tu Diep

2. FLOATING AND SINKING
 An object floats when it rests on top of a liquid or
when it rises in the air. Apples float in water. Hot air
balloons float in the air.

3. FLOATING AND SINKING
 An object sink when it drop down in liquid or
when it falls down through the air. Rocks
sink in water. Rock should also sink in air. If
the pebbles can’t float in water. They
couldn’t float in air either.

4. WHAT FLOATS? WHAT SINKS?
 Solid objects are not the only things that float and
sink. Liquids and gases do too.
A bubble is a liquid with gas inside it. Bubbles float.

5.  Corn oil and syrup are both liquids. Corn oil floats in
syrup.
Corn Oil
Colored Water

6. MILK AND CHOCOLATE SYRUP ARE LIQUIDS. BUT
ONE IS DENSER THAN THE OTHER
If you’ve ever poured chocolate syrup into milk,
then you know that the sauce will sink.

7. AIR
The air in our environment is made up
of many gases.
The air we breathe here on Earth is
made up of different gases. It contains
around 78% nitrogen, 21% oxygen,
1% argon and a small amount of other
gases.

8. GAS
Helium balloons float in the air.
The helium inside these
balloons allow the balloons to
float. Gases such as propane
and butane do not float in air.

9. DENSITY
 All solids, liquids, and gases have density.
 Density is how heavy something is
compared to its size.
This bowling ball
isn’t very big but
it is very dense
so it is extremely
heavy.

10. DENSITY
 These candy treats are about the same size. One is
solid chocolate. The other has a lot of air inside.
The solid chocolate has more density.

11. WHAT FLOATS? WHAT SINKS?
 Object will sink if they have more density than the
liquid or gas they are in.
 http://youtu.be/RUMX_b_m3Js

12. WHAT FLOAT? WHAT SINK?

14. WHY DO THINGS FLOAT? AN EASY LESSON
http://youtu.be/y0SnFCs9z1g
Have you ever heard the story of Archimedes, an ancient Greek
scientist? One day, he noticed the water level rising when he got
into his bathtub. He was so excited, he hopped up and ran out into
the street stark naked, shouting, "Eureka!" ("I've found it!")

15. DISCUSSION
 If something is heavier than another, does this mean
that the heavier item will sink? Not necessarily, because
a really heavy boat floats yet a light penny sinks. But a
boat has to be careful not to overload itself as it could
reach a point where it becomes too heavy and could
sink.
 Does the shape of an object determine whether an
object sinks or floats? Sometimes it does. If you make a
tin foil ball that sinks, you can then stretch out the tin foil
and make it float. It is the same weight, but the weight is
spread out across a larger space (change in density).
 The peel on the orange is spongy and full of air pockets,
thus allowing the orange to float. Once the peel is
removed, the ‘naked’ orange sinks. The orange peel
acts like a life jacket which helps humans to float when
in water.

16. EXTRAS
 The following slides contains extra information
about this topic that you can add to the program if
you’re doing a longer program or a program for
older kids.

17. ARCHIMEDES’ PRINCIPLE
 Archimedes’ principle is better known as the law
of buoyancy (the ability to float in a liquid or to rise
in a fluid ).
It states: Something submerged(partially or fully) in
water experiences a force that tries to push it up
(and out of the water). The amount of that force is
exactly equal to the WEIGHT of the WATER that
the object is displacing.
The following video website (video included)
provides a great review of Archimedes' Principle
 http://youtu.be/eQsmq3Hu9HA
 http://youtu.be/qvlurmJNDEw

18. LIQUID DENSITY
http://youtu.be/fE2KQzLUVA4

19. LIQUID DENSITY
This test tube contains
corn syrup on the bottom,
colored water in the
middle, and oil on the top

21. Liquid Density
 Density is mass (how
many atoms are in an
object) divided by
volume.
 The more atoms a
liquid contains the
denser it will be.

24. REFERENCES
 What floats? What sinks? : a look at density /
Jennifer Boothroyd.
 www.science4mykids.com