Transcript mystery milk

Milk Project
Materials:

- Milk
- Pie tin
- Food coloring (red, yellow,
green, blue)
- Dish-washing soap
- Cotton swabs
Steps:
 1. Pour enough
milk in the
pie tin to completely cover the
bottom and allow it to settle.
 2. Add one drop of
each of the four colors
of food coloring - red, yellow,
blue, and green - to the milk.
Keep the drops close together
in the center of the plate.

3. Use a clean cotton swab.
Predict what will happen when
you touch the tip of the cotton
swab to the center of the milk.
It's important not to stir the mix
just touch it with the tip of the
cotton swab.

4. Next, place a drop of liquid
dish soap (“Dawn” works well) on the
other tip of the cotton swab.
Place it in the middle of the
milk. Hold it there for 10-15 s.
Observed:
Look at that
burst of color!
It's like the
4th of July in a
bowl of milk:
mini-explosions
of color.
5. Add
another drop of soap to the tip
to the cotton swab and try it again.
Experiment with placing the cotton
swab at different places in the milk.
Observe that the colors in the milk
continue to move even when the
cotton swab is removed.
Why does the food coloring in the milk move?
How does it work?

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Hypothesize how and why you
think that this occurs.
What makes the
swirling of the food
coloring occur?
Talk
about it with
your partner.
Then write your ideas in your
science journals.
What make the swirling of the
food coloring occur?

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Liquid soap wrecks the surface
tension by breaking the cohesive
bonds between water molecules and
allowing the colors to zing
throughout the milk.
The liquid soap weakens the milk’s
bonds by attaching to its fat globules
because of its bipolar characteristics
(hydrophilic, water-loving, on one end
and hydrophobic, water-fearing on the
other).
What is it about soap that
allows for oils to be dissolved?

The soap's hydrophilic end dissolves in
water and its water-fearing end attaches to
a fat globule in the milk.

The soap molecule’s water-loving part is
polar and the water-fearing is nonpolar.
When we wash with water alone, we
cannot dissolve oils, but when soap is
added to the water, the polar end of the
soap molecules is attracted to the polar
end of the water molecules and the
nonpolar end is absorbed into the oil. A
particle (larger than a molecule) is formed
and the oil can be washed away.
What is it about milk that makes it
have surface tension?

Since milk is mostly water, it has
surface tension like water. The
drops of food coloring floating
on the surface tend to stay put.
Water has surface tension
because of the attraction of all of
the molecules, cohesion. In the
bulk of the liquid each molecule
is pulled equally in all directions
by neighboring liquid molecules.
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Atom: the smallest basic unit of
matter.
Element: one type of atom (each
have different number of protons)
Molecules: two or more atoms held
together by a chemical bond.
Compound: atoms of different
elements bonded together in a
certain ratio.
Unique Properties of water

This experiment
can explain
surface tension
and polarity.

The explanation
of surface
tension can
show all of the
things that
make water so
useful for life.
 So, water’s surface tension comes
from its polarity so it attracts itself.
This makes certain things like the
capillary effect possible so that
plants may “drink” water from the
ground.
 This also
explains the
structure of ice
and why the
solid form of
H2O is less
dense than the
liquid stage.
Phospholipid Bilayer

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This characteristic
behavior of water and
oil is of critical
importance for living
things, determining
many properties of the
cell
Phospholipids, the
building blocks of the
cell membranes, are
both hydrophilic and
hydrophobic.

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The hydrophobic pair of fatty acids
are embedded in the middle of the
membrane.
The hydrophilic phosphate projects
outward forming hydrogen bonds
with a tight, organized layer of
water on each face of the
membrane.
Do you drink homogenized milk?

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This experiment explains what
homogenization of milk is. Milk is
made up mostly of water and
then equal parts of protein, fats,
and sugar. Homogenization
breaks up the fat and spreads it
throughout the milk into tiny
pieces of fat called globules.
When the milk was first placed
into the carton, it was still and did
not move. Even when the food
coloring was added to the milk,
things were still quiet. This is
because the fat globules were
steady and undisturbed.

When the soap hits the milk, things
begin to move. The soap breaks up
the fat globules and lets them spread
across the surface of the milk. When
you add soap, the weak chemical
bonds that hold the proteins in
solution are altered.

As the globules break and expand,
they create movement in the milk.
Normally you would never notice
this, but the food coloring shows how
the surface of the milk moves and
changes in response to the soap
breaking up the fat in the milk.
How soap works

Soap
Soap has a part of the molecule
that is polar and nonpolar.
When washing with water alone,
it will not dissolve oils, but when
soap is added to the water, the
polar end of the soap molecules
is attracted to the polar end of
the water molecules and the
nonpolar end is absorbed into
the oil. A particle (larger than a
molecule) is formed and the oil
can be washed away with water.

In this experiment the liquid
soap weakens the milk’s bonds
by attaching to its fat globules
because of its bipolar
characteristics (hydrophilic on
one end and hydrophobic on the
other). The soap's hydrophilic
end dissolves in water and its
water-fearing end attaches to a
fat globule in the milk.
What is the polar side of the polar side
of soap called?