Archive for 2012
Part A
Materials that are needed:
-sugar
-a spoon
-a candle
-butter
-candle wax
-a spoonful of flour
-a beaker of water
-a beaker half-filled with vinegar
-a teaspoon of baking soda
What i and my friends did?
1.heating sugar,butter and candle wax.
2.cooling the sugar,butter and candle wax after it was heated.
3.Observe if there was a new material formed.
4.Identify if it is a physical or a chemical change.
5.Identify if it is a reversible change or a non-reversible change.
6.Fill in the table in the science workbook page 49.(Observations and results).
What i and my friends did?
1.add a spoonful of flour into the beaker of water and observe what happened.
2.add a teaspoon of baking soda into the beaker half-filled with vinegar.
3.fill in the table in the science workbook page 50(Observations and results).
4.fill in the conclusion part on page 50 too.
What is a reversible change?
-When materials go through a reversible change,they can be changed back to their original form.
What is a non-reversible change?
-When materials go through a non-reversible change,they cannot be changed back into their original form.Chemical changes are usually non-reversible.
http://www.youtube.com/watch?v=bm5UktYcybk Changes around us!
http://www.youtube.com/watch?v=Z-lGJ82Blt0 Reversible and non-reversible change video!
Here are some pictures when i and my friends do the science experiment!
Materials that are needed:
-sugar
-a spoon
-a candle
-butter
-candle wax
-a spoonful of flour
-a beaker of water
-a beaker half-filled with vinegar
-a teaspoon of baking soda
What i and my friends did?
1.heating sugar,butter and candle wax.
2.cooling the sugar,butter and candle wax after it was heated.
3.Observe if there was a new material formed.
4.Identify if it is a physical or a chemical change.
5.Identify if it is a reversible change or a non-reversible change.
6.Fill in the table in the science workbook page 49.(Observations and results).
Part B
What i and my friends did?
1.add a spoonful of flour into the beaker of water and observe what happened.
2.add a teaspoon of baking soda into the beaker half-filled with vinegar.
3.fill in the table in the science workbook page 50(Observations and results).
4.fill in the conclusion part on page 50 too.
What is a reversible change?
-When materials go through a reversible change,they can be changed back to their original form.
What is a non-reversible change?
-When materials go through a non-reversible change,they cannot be changed back into their original form.Chemical changes are usually non-reversible.
http://www.youtube.com/watch?v=bm5UktYcybk Changes around us!
http://www.youtube.com/watch?v=Z-lGJ82Blt0 Reversible and non-reversible change video!
Here are some pictures when i and my friends do the science experiment!
Cells are made up of parts that enable them to function.Animal cell and plant cell are made up of many parts.
Animal Cell:
-cytoplasm
-a nucleus
-a cell membrane
-vacoules
Vacoules are small cavities inside the cell which play role in the digestion inside the cell.
Cytoplasm is a jelly-like substance that is found in all cells.It allows substances such as food and oxygen to be transported around the cell.
Nucleus is found in the the cytoplasm.It controls everything that happen in the cell.There are thread-like structures in the nucleus.they contain information on how the cells should function.
Cell membrane holds the cytoplasm inside it.It controls the substances that go into or out of the cell.
Plant cell:
-cytoplasm
-a nucleus
-a cell membrance
-a vacuole
-a cell wall
Vacoule help plants to stand upright as plants do not have skeletal system to provide support.
Cell wall is made of a stiff material that gives the plant its shape.
Chloroplast contain chlorophyll,the green pigment that traps sunlight to make food for the plant.
Cells also multiply to replace old cells that die.This process take place in organisms all the time.
Multicellular organisms
human beings
As we grow,our body increases in size.This is because the number of cells in our body increases.Our body multiply by a process known as cell division.The nucleus and the cytoplasm of one cell divide to produce two cells.The new produced cells are identical to the original cells.
Our skin cells can live up to three weeks,while cells lining on our intestines are replaced by new cells every three days.Some cells also help to repair our damaged part of our body.
Unicellular organisms
Bacteria and paramecia
Unicellular organisms,such as bacteria and paramecia,multiply by dividing theselves.
Yeast
During the process of budding,a small bud grows from a yeast cell.The bud then increases in size and breaks away from the original yeast cell.
From cell to organism
Human:
Cell>Tissue>Organ>System>Organism
Plants:
Cell>Tissue>Organ>System>Organism
Energy in cells
An organism needs energy because its cells need energy to grow and divide themselves.
1.Nutrients enter the cell through the cell membrane.
2.The cell converts the nutrients into energy.This is used by the cell for cell division,growth and repair.
http://www.youtube.com/watch?v=wJyUtbn0O5Y
Information in cells
When organism reproduce,they pass on certain characteristics or genetic traits to their young.These characteristics are contained as genes and stored in the thread-like structures in the cell nucleus.
Animal Cell:
-cytoplasm
-a nucleus
-a cell membrane
-vacoules
Vacoules are small cavities inside the cell which play role in the digestion inside the cell.
Cytoplasm is a jelly-like substance that is found in all cells.It allows substances such as food and oxygen to be transported around the cell.
Nucleus is found in the the cytoplasm.It controls everything that happen in the cell.There are thread-like structures in the nucleus.they contain information on how the cells should function.
Cell membrane holds the cytoplasm inside it.It controls the substances that go into or out of the cell.
Plant cell:
-cytoplasm
-a nucleus
-a cell membrance
-a vacuole
-a cell wall
Vacoule help plants to stand upright as plants do not have skeletal system to provide support.
Cell wall is made of a stiff material that gives the plant its shape.
Chloroplast contain chlorophyll,the green pigment that traps sunlight to make food for the plant.
Cells also multiply to replace old cells that die.This process take place in organisms all the time.
Multicellular organisms
human beings
As we grow,our body increases in size.This is because the number of cells in our body increases.Our body multiply by a process known as cell division.The nucleus and the cytoplasm of one cell divide to produce two cells.The new produced cells are identical to the original cells.
Our skin cells can live up to three weeks,while cells lining on our intestines are replaced by new cells every three days.Some cells also help to repair our damaged part of our body.
Unicellular organisms
Bacteria and paramecia
Unicellular organisms,such as bacteria and paramecia,multiply by dividing theselves.
Yeast
During the process of budding,a small bud grows from a yeast cell.The bud then increases in size and breaks away from the original yeast cell.
From cell to organism
Human:
Cell>Tissue>Organ>System>Organism
Plants:
Cell>Tissue>Organ>System>Organism
Energy in cells
An organism needs energy because its cells need energy to grow and divide themselves.
1.Nutrients enter the cell through the cell membrane.
2.The cell converts the nutrients into energy.This is used by the cell for cell division,growth and repair.
http://www.youtube.com/watch?v=wJyUtbn0O5Y
Information in cells
When organism reproduce,they pass on certain characteristics or genetic traits to their young.These characteristics are contained as genes and stored in the thread-like structures in the cell nucleus.
these are the materials that we need for the experiment:
We have 2 bottles A and B.
First,we put yeast and water to bottle A while bottle B have sugar,water and yeast.
Second,we put a balloon on top of each bottle.
After how many minutes,we check on the balloon,the balloon on bottle B was bigger in length than bottle A because we measure it with a ruler.
Then,we do it for many times and as a result,the balloon on bottle B is bigger.
The balloon on bottle B inflates bigger because it has sugar in it,the sugar is like the energy.
First,we put yeast and water to bottle A while bottle B have sugar,water and yeast.
Second,we put a balloon on top of each bottle.
After how many minutes,we check on the balloon,the balloon on bottle B was bigger in length than bottle A because we measure it with a ruler.
Then,we do it for many times and as a result,the balloon on bottle B is bigger.
Is Air Really There?
If you go to your closet andtake all your stuff out, is it
really empty?
If you uncap a bottle of soda and
pour its contents in a glass, is the
bottle really empty?
If you open a can of food and
pour it into a bowl, is the can
really empty?
The answer to all of these questions
is “no”, because air is still inside the
containers. As soon as you take the
stuff out of your closet, pour your
soda in a glass, or pour the food
out of the can, air flows inside to
fill the “empty” space.
If you don’t believe it, ask an
adult to help you try this…
1. Empty a small bottle of water
or soda.
2. Turn the bottle upside down, so
that the opening points down,
and push it into a large bucket
or sink filled with water.
3. Slowly flip the bottle right side up
again while keeping it underwater.
What happened? Did you see
bubbles? What was in the bubbles?
Did the bottle stay empty?
When you turned the bottle right
side up again, the air that was
trapped inside the bottle escaped as
bubbles. The water that was inside
the bucket or sink flowed into the
bottle until it was full. So the bottle
was never really “empty”.
A space that is truly empty is called
a vacuum. On Earth, we don’t have
any truly empty spaces, because
air––or something else—is
everywhere. But we can remove
some of the air from a place
temporarily. One way to do this
is with a vacuum cleaner.
A compartment in the middle of a
vacuum cleaner catches dust and
dirt in a bag. A small hole for
attaching a hose is at one end of
the compartment, and a fan is at
the other. Most vacuum cleaners
also have other parts, like beater
brushes and nozzles, but inside they
are all about the same. They have a
dust compartment (which may have
a bag in it), a hose (with a nozzle
on the end), and a fan. See the
illustration below.
When you turn on a vacuum cleaner,
the fan inside starts to spin very
quickly. The fan is positioned so
that it pulls air out of the dust
compartment and blows it out the
back of the vacuum cleaner. As a
result, air must rush through the
hose at the other end to refill the
dust canister. Because the fan blows
the air out of the vacuum cleaner
faster than the air can race through
the hose to refill it, a “partial
vacuum” occurs. The result is that
the vacuum cleaner sucks air and
dust through the hose, helping us
clean our floors and carpets.
http://portal.acs.org/portal/PublicWebSite/education/whatischemistry/scienceforkids/articles/CSTA_015161
