The accident

Okay welcome back! Today, it would the last post and and as promised, I would tell you what happened in the laboratory. So, relax cause it involves of breaking of beaker.

Okay, the whole class was supposed an experiment of photosynthesis and test for the presence of starch in the leaf. So, we were supposed to boil the leaf in the water and then take the leaf out. But the leaf in inside another beaker so its like there is a small beaker inside a bigger beaker. So, I when take out, it slipped out my hand it go ''Bang''! And, it broke. I went to tell the teacher. He told us to sweep all the glass broken pieces and throw it away. It was very close as the beaker actually almost spill on me. Let me tell you secret, actually I did not wear my goggles.

The lesson here is tell you how important it is to wear a safety goggles before do your experiment. If not, you are risking your eyes. Ok, I would like wish you all luck for your coming end of year exams so wish me luck too!(:

Term 3 science test result

Okay guys, I'm back! You all must be wondering what my result is. As I mentioned in the previous post, I will be working hard towards my goal, which was a B3. Okay, now, its the moment of glory, and my result is......... 27 out of 40. It is a B3 so I have at least achieve my GOAL! But it is still a pity that I am short of 1 mark and I could have gotten an A2. But, what's over is over.

Okay, let me tell you what I did during term 3. Okay, basically, I paid more attention in class than what I paid in class during term 2. I also bought assement books to add on to revision. I also bought guide book to help me. They really did aid me in my revision and I am very glad. The slides in the IVLE also serve their puposes too! Actually, the last four days, I ''chiong''! I spent alot time on revising my science. As my chinese test and science test were on the same day, I actually must admit that I worked very hard for these two tests than my psle. Or maybe the whole term 3. The day before tests, I study still midnight before I sleep.

Okay, guys the learning point for this lesson is that as long you are willing to work hard, they would definitely pays off! So, believe me, work hard and you see the results!(: Look forward for my last post next week, as it is about an accident in the laboraty......

Term 2 science results

Hey guys, I'm back!(: Although I have said the previous post was the last lesson of the session, but this post is compulsory. Maybe another two posts. These three posts all talks about example my term science results, about some laboratory lessons or mt experience with science. Okay, so today about term 2 science results.

Sorry to disappoint you, but my term result, I got 21.5 out of 40 which was a C6. This totally disappointed me. I must admit that I did not study hard for the test mainly because I did not listen in class thus I missed out some points to study. The prefix symbols all these, I actually did not take note that it would be tested. I thought about the marks and I did some reflections. I promised myself to pay more attention in class during term 3 and aim at least a B3( worst case scenario).

So, guys, what I am trying to say is that the results is not the end, but is the reflections you made, take note of the learning points. Make sure you work harder towards your goals and achieve your objectives. So, good luck!(: Me too!(:

The last lesson--Respiration and Photosynthesis

Okay, since today is your lesson, I shall make the lesson quite short. Enjoy! After this session, I would be studying for my final year exam so I would be very busy and still feel free ask me any questions.
What is photosynthesis?

• process by which plants use carbon dioxide, water and light trapped by chlorophyll to make food in the form of glucose, with oxygen given out during the process.
• the word equation is : carbon dioxide + water --(light + chlorophyll)-->> Oxygen + glucose
• takes place in the chloroplast which contains chlorophyll

The importance of Photosynthesis

• make chemical energy available to animals
• removes carbon dioxide and provides oxygen

Photosynthesis makes chemical energy available to animals

• plants provide organisms with food and energy to live directly or indirectly.
• plants are the primary food source because they made their own food.
• plants are called producers

What is aerobic respiration?

• is the process whereby food substances are broken down in the presence of oxygen with the release of energy in the living cells. Carbon dioxide and water are released as waste products.
• word equation is : oxygen + glucose -----> water + carbon dioxide + energy

What is Tissue Respiration?

• process food substances are broken down in living cells
• a large amount of energy is released for the cell to perform different activities

What is External Respiration?

• process of bring the oxygen from the surrounding environment to the cells for tissue respiration to take place.
• also responsible for removing from the body the carbon dioxide and water formed during tissue respiration
  
• breathing is part of external respiration

The importance of Aerobic Respiration:
--Most organisms respire acrobatically. Energy released is used for:

• Growth
• Muscle contractions
• Digestion and absorption of food substances
• cell division
  

Breathing

• The physical process by which respiratory gases are exchanged with the surroundings
• movement that brings the air and into and out of the body

What is Anaerobic Respiration?

• is the breakdown of food substances in the absence of oxygen.
• releases less energy than Aerobic Respiration
• word equation of anaerobic respiration in humans : glucose ----> Lactic Acid + Energy
• word equation of anaerobic respiration in yeast : glucose --> carbon dioxide +Ethanol + Energy
  

Differences between Respiration and Photosynthesis :

Respiration Photosynthesis
-uses oxygen -produces oxygen
-uses food -produces its own food
-does not need chlorophyll -needs chlorophyll
-produce carbon dioxide -uses carbon dioxide
-takes place all the time -requires sunlight
-takes place in all living things -takes place in green plants
-takes place in all living cells -takes place in cells that contains chlorophyll
-energy is liberated -energy is stored in carbohydrate molecule
-oxygen is used, carbon dioxide and water -carbon dioxide and water are used, oxygen is used
are given out
-a destructive process, resulting in the -constructive process, resulting in building up
of carbohydrate molecule
breakdown of carbohydrate molecules
-occurs at all times in all cells, independent -occurs in cells which contains chlorophyll the under the presence of sunlight
of chlorophyll and sunlight

Similarity between Respiration and Photosynthesis

• Both involve energy
• Both involve enzymes

Okay, that's all. Thanks for all your support!! This marks our last lesson!! Goodbye!(:

Compund and mixtures

Welcome back again! Today, we will be talking about compound and mixtures. Button your seats belts and let's rock and roll!

What is a compound?

• is a substance consisting of two or more elements chemically combined together.
  

Examples of compounds:
1. Sodium Chloride Elements: Sodium Chlorine
2. Water Elements: Hydrogen, Oxygen
3. Copper (||) sulfate Elements: Copper, Sulfur, Oxygen
4. Carbon dioxide Elements : Carbon, Oxygen

Characteristics of Compounds:

• has different properties that are different from the properties of its constituent elements
• when compound is formed, there is usually an exchange of energy (in form of heat energy or light energy or both) with their surroundings.
  
• can only be broken down into simpler substances by chemical methods, such as decomposition by heat energy , exposure to light or passing through electric current through it.
• the different elements in a compound always join together in a fixed proportion by mass.

What is a mixture?

• consists of two or more substances not chemically combined together.
  

Examples of mixtures:

1. Blood
   
2. Soil
3. Air
4. Sea water
5. Aerated water

Characteristics of Mixture

• has the properties of its components
• when mixture is produced, little or no energy in the form of heat energy or light energy is given out or taken in.
• can be separated into its components by physical methods like using a magnet, evaporation, filtration and distillation
• can be mixed in any proportion by mass
  

Now, together with the previous lesson. We shall see the differences....

Differences between element, compound and mixture:
Elements Compound
-made up of only one atom -different elements in a compound
- simplest pure substance -combine in a fixed proportion by mass
-have properties similar to -a chemical change takes place when compound is formed
their atom - has properties which are different from its constituents elements
-cannot be broken down - can only be broken down by chemical methods like heating

Mixtures
-components in a mixture are not mixed in any fixed proportion
-no chemical reactions takes place when mixture is formed.
-mixture has properties of substances of which it is made.
-can easily be separated by physical methods like using a magnet

Okay, that's all for today! Hope you have learn something useful today! Enjoy! And remember to tune in for the last lesson of this season!!! Enjoy!(:

Elements

Hey welcome back! Today, we would learning about elements!!(:

What is element?

• a substance which cannot be split into two or more by chemical reaction.
• every element is given a name and chemical symbol
• 1o9 elements are discovered so far
• 92 are natural element while others are man-made
• Most elements are found combined with other elements in the form of ores and minerals

Classification of elements:
http://www.bpc.edu/mathscience/chemistry/images/periodic_table_of_elements.jpg

Elements are classified according to their chemical properties into a chart called a Periodic table which can be seen from the above link.

In the periodic table:

• Each vertical column is called a group
• Each element in a group has a similar chemical properties
• Each group has its own unique properties
• Each horizontal row is called a period
• Elements from right to left show a gradual change from metallic elements to non-metallic elements

Physical properties of Metallic and non-metallic elements

Metallic elements Non-metallic elements
1. High boiling and melting points. 1. Low boiling and melting points
2. Good conductors of heat 2. Poor conductors of heat
3. Good conductors of electricity 3. Poor conductors of electricity
4. Ductile ( can be drawn into wires) 4. Snap easily
5. Malleable (can be beaten into shapes without breaking) 5. Brittle( easily broken)
6. Shiny 6. Dull in appearance
7. High in density 7. Low in density
8. Sonorous 8. Not sonorous

Uses of some non-metallic elements:

1. Carbon Uses: Pencil lead, fuel, constitutes living tissues
2. Nitrogen Uses: fertilizers, freezing agent for food, constitutes plants and animal proteins
3. Sulfur Uses: harden rubber, pesticides, drugs, fireworks
4. Iodine Uses: antiseptic
5. Oxygen Uses: respiration, combustion
6. Chlorine Uses: bleaching powder, kills bacteria, used in making plastics
7. Fluorine Uses: prevents tooth decay
8. Silicon Uses: transistors, manufacture of steel

Uses of some metallic elements:

1. Zinc Uses: to coat iron sheets to make galvanized iron
2. Mercury Uses: thermometers, fluorescent lamps, dental fillings
3. Magnesium Uses: used to distress flares, fireworks
4. Aluminum Uses: aeroplane parts, dink cans, cooking utensils, ladders
5. Copper Uses: electrical wires, water pipes, switches, coins, tanks
6. Calcium Uses: for the body to grow strong teeth and bones
7. Iron Uses: manufacture of steel, railings, grills, cooking utensils
8. Lead Uses: lead shots, accumulators
   

Okay, that;s all for today's lesson. Hope you and enjoy and remember to tune next week for the lesson on compounds and mixture! (: