1. Chapter 4 Grouping and Changing Materials Glycerine and
Bubbles Matthayomsuksa 1
2. Glycerine and Bubbles
3. Vocabula ry Structure Scientific Experime nt Glycerine and
Bubbles
4. liquid (n.) a substance that is not a solid or a gas Ex.
Water and milk are liquids.
5. colorless (adj.) having no color Ex. Glycerine is colorless
and sweet tasting.
6. dissolve (v.) become part of liquid Ex. Glycerine can be
dissolved easily.
7. surface (n.) the outside or top layer of something Ex. The
glycerine in the bubble mixture will stay right at the soap film
surface.
8. evaporate (v.) to change into vapor Ex. Water is
continuously evaporating from a soap bubble.
9. supple (adj.) bending and moving easily and gracefully Ex.
It is said that the glycerine makes a soap film supple.
10. Adverb 1. In most cases, an adverb is formed by adding
'-ly' to an adjective: Adjective Adverb cheap quick slow cheaply
quickly slowly Examples: Time goes quickly. He walked slowly to the
door. She certainly had an interesting life. He carefully picked up
the sleeping child.
11. Rules If the adjective ends in '-y', replace the 'y' with
'i' and add '-ly': Adjective Adverb easy angry happy lucky easily
angrily happily luckily If the adjective ends in -'able', '-ible',
or '-le', replace the '-e' with '-y': Adjective Adverb probable
terrible gentle probably terribly gently
12. If the adjective ends in '-ic', add '-ally': Adjective
Adverb basic economic tragic basically economically tragically
13. What is glycerine? Glycerine is a thick liquid that is
colorless and sweet tasting. It has a high boiling point and
freezes to a paste. Glycerine's most common use is in soap and
other beauty products like lotions, though it is also used, in the
form of nitroglycerin, to create dynamite. Glycerine can be
dissolved easily into alcohol and water but not into oils.
Glycerine and Bubbles Glycerine in soap bubble mixtures Most good
soap bubble recipes mention glycerine. The Glycerine (or glycerol)
improves the soap bubble mixture in two ways: It increases the
lifetime of the bubbles, and it makes the bubbles suppler.
14. Glycerine increases the lifetime of the bubbles Water is
continuously evaporating from a soap bubble. As a result of this
process the soap film becomes thinner and thinner until it breaks.
The glycerine in the bubble mixture will stay right at the soap
film surface, and will therefore reduce the number of water
molecules at the surface. As a result the evaporation will be
slower in a soap film with glycerine, because it is always water
from the surface that disappears from the soap film during the
evaporation process. The glycerine molecules attract water
molecules and form weak chemical bonds, the so-called hydrogen
bonds. These bonds make it more difficult for the water molecules
to leave the surface. One can say that it gets more difficult for
the water to evaporate, since the glycerine is pulling the water
back into the soap film. For these reasons soap bubbles will
generally have a longer life span if they contain glycerine.
15. Right: Soap film with glycerine. The glycerin is positioned
at the surface of the film and thereby inhibits the evaporation of
water. Glycerine makes the soap films suppler It is said that the
glycerine makes a soap film suppler, more flexible. The explanation
is supposedly that the glycerine molecules will go in-between the
soap molecules. When the film is bending, the long (and charged)
soap molecules will move around the smaller glycerine molecules
instead of moving around other big (and charged) soap molecules.
This gives that soap molecules more freedom of movement and
therefore makes the film more flexible. According to many soap
bubble recipes, the bubble mixture should be prepared hours before
use. An explanation for this could be that the glycerine needs time
to become packed in-between the soap molecules. Left: Soap film
without glycerine. The film only contains water and soap molecules.
The evaporation of water from the film is relatively large.
16. The best bubbles in the world! Equipment -washing-up liquid
-water -glycerine -containers -wands Directions -Get into a group
of 3 people. -Bring out the equipment and go to your group. -Do an
experiment according to the process below.
17. Process 1. Mix washing-up liquid and water in each
container. Container 1: 40 per cent washing-up liquid Container 2:
30 per cent washing-up liquid Container 3: 20 per cent washing-up
liquid Container 4: 10 per cent washing-up liquid 2. Add glycerine
into each container. Describe properties of glycerine ... 3. Blow
the four wands and notice the bubbles.
18. Use each of the four containers and try to blow four
bubbles each time. When the bubbles work, tick a box for that
container. If the bubbles dont work, put a cross.
