Photosynthesis and Respiration

In this lesson, we learn about Photosynthesis and respiration.
Photosynthesis takes place in the presence of carbon dioxide, water, light and chlorophyll. It is the process which plants do to produce food. Photosynthesis also removes carbon dioxide and provides oxygen.

Aerobic respiration is the process by which glucose and oxygen are broken down into carbon dioxide, water and energy.It is a bit like the reverse of photosynthesis

The magnesium ribbon

In this lesson, we did an experiment on compound. We were told to place the magnesium ribbon over the flame and see what happen next. Yue Heng and i broke the magnesium ribbon into two as we both wanted to try. When the magnesium ribbon was placed over the flame, it glowed so brightly that it could blind us. No wonder the worksheet told us not to stare at it.......
We also discussed about compounds in class. We were also taught how to write a word equation.

Elements, Compounds and Mixtures!!

This was the coolest experiment that i tried in my whole life!!!!

We were to find out the properties between a mixture and a compound. We learnt that sulpher and iron will become a mixture when mixed and when heated, a compound is formed. Sulfer is yellowish and powderish. We also found out that it could not be attracted to the magnet. After that we observed some iron fillings and found out that it was black, needle-like and that it ATTRACTED to the magnet. Next, we mixed the both items together and formed a mixture. It was yellowish and black and still powderish. Then we heated the two items together and formed a compound. The mixture melts and formed a black solid. The compound could not be attracted to the magnet. T.T! Then we discussed about some facts about the compound and mixture with our Science Teacher, Ms Leong and found out that the heat had distroyed some of the properties. Then we moved on to naming some new elements.

Science Ace 2!!!

This was my second Ace project!!


Name: Tan Jin Neng, Clarence
Class: 1A3 (28)
Term 3 Science Ace
Experiment on obtaining water from salt water
Introduction:
Mixtures are not chemically joined and we can use physical methods to obtain the components of the mixture. The various separation techniques are Filtering, Chromatography, Distillation, Fractional Distillation and Evaporation.
A solution is a mixture. It is formed when a solid, a liquid or a gas dissolves in a liquid. For example, if you stir salt into water, the salt dissolves. It breaks up into individual salt molecules. The solution is now a mixture of water molecules and salt molecules. The salt is called the solute and the water is called the solvent.
Experiment set up:
As we have learnt that we can obtain a solvent from a solution using distillation, I shall do an experiment on distillation to obtain water from salt solution, not in the laboratory but at home. Since it is at home, I do not have the necessary laboratory apparatus like flask, Bunsen burner, condenser, etc, I shall make use of some kitchen utensils.
These are the things that I am going to use for the experiment: A cup of water, some salt (sodium chloride), an empty saucer, cooking pot, aluminum foil, ice cubes and a spoon.
First, I shall dissolve some salt into the water. Stir it until the salt dissolves.
Next I pour the salt solution into the cooking pot.
Place the pot onto a stove. Place the empty saucer in the cooking pot. Cover the pot with an aluminum foil and put some ice cubes on the foil.
Heat the salt solution until all the ice cubes have melted.
Remove the aluminum foil and take out the saucer from the cooking pot.
Some water is collected in the saucer. We can further test if the water is pure by boiling it. If it boils at 100°C, it means the water is pure.

Conclusion:
The melting and boiling points of salt and water are tabulated below:
Salt Water
Boiling point 1413°C 100°C
Melting point 801°C 0°C

As water has a lower boiling point than salt, 100°C (water) compared to 1413°C (salt), water evaporates first when the salt solution is heated. Water vapour condenses to form water droplets when in contact with a cool surface which is the aluminum foil with ice cubes on it. As the weight of the ice cubes form a depression on the centre of the aluminum foil, the water droplets then drip into the saucer. The salt will not evaporate yet as its boiling point is 1413°C and therefore is left in the pot.



These are the link to my videos as i cannot upload them ):
http://www.youtube.com/watch?v=xPICTyqui40
http://www.youtube.com/watch?v=eeipv9xCdtM
http://www.youtube.com/watch?v=HtfOQLt4QRs

Separation Techniques 2(:

We also did another experiment on another time on another day about Paper chromatography. It is actually using filter paper to separate inks. First, we used a pencil to draw a line across the scrip of paper which is about 3-5 cm away from the bottom. Next we drip a drop of ink onto the line. We then place the paper into a test-tube containing ethanol. Magically, the ink separated into 3 colours such as red, purple and black.

I tried doing the experiment at home using normal paper and water but it failed :(

Separation Techniques 1

In this lesson, we were asked to separate a mixture of sand, water and salt which is also called a suspension. We poured the mixture into a filter paper which was folded in to a cone like shape. I was surprised when the filtrate came out as i thought it would still be not clear, but instead it was crystal clear. We then poured the filtrate into a evaporation disk and started boiling it. We separated salt from salt water!!!

First time in the LAB!!!

I feel that this science lesson is very interesting as it is my first time entering the laboratory. The laboratory is filled with items used for experimenting for example, the test tubes which is kept in the side of our classrooms.

We learnt about the different signs in the lab.such as the flammable sign and explosive sign
we also brought our test-tube there and kept it at the side of the the room