Laboratory Lessons (Safety)

Lab lessons can be fun and enjoyable but we must follow some simple rules to make it a memorable experience.

1. Conduct yourself in a responsible manner at all times in the laboratory.


2. Follow all written and verbal instructions carefully. If you do not understand a direction or part of a procedure, ASK YOUR TEACHER BEFORE PROCEEDING WITH THE ACTIVITY.

3. Never work alone in the laboratory. No student may work in the science classroom without the presence of the teacher.

4. When first entering a science room, do not touch any equipment, chemicals, or other materials in the laboratory area until you are instructed to do so.


5. Perform only those experiments authorized by your teacher. Carefully follow all instructions, both written and oral. Unauthorized experiments are not allowed.


6. Do not eat food, drink beverages, or chew gum in the laboratory. Do not use laboratory glassware as containers for food or beverages.



7. Be prepared for your work in the laboratory. Read all procedures thoroughly before entering the laboratory. Never fool around in the laboratory. Horseplay, practical jokes, and pranks are dangerous and prohibited.

8. Always work in a well-ventilated area.


9. Observe good housekeeping practices. Work areas should be kept clean and tidy at all times.


10. Be alert and proceed with caution at all times in the laboratory. Notify the teacher immediately of any unsafe conditions you observe.



Remember the tops and have an enjoyable time!

NEWATER

Process
NEWater is the product from a multiple barrier water reclamation process:

The first barrier is the conventional wastewater treatment process whereby the used water is treated in the Water Reclamation Plants.
The second barrier, and first stage of the NEWater production process, uses microfiltration/ultrafiltration to filter out suspended solids, colloidal particles, disease-causing bacteria, some viruses and protozoan cysts. The filtered water that goes through the membrane contains only dissolved salts and organic molecules.
The third barrier, and second stage of the NEWater production process, utilizes reverse osmosis (RO). In RO, a semi-permeable membrane filters out undesirable contaminants such as bacteria, viruses, heavy metals, nitrate, chloride, sulphate, disinfection by-products, aromatic hydrocarbons, and pesticides that cannot pass through the membrane. Hence, NEWater is free from viruses and bacteria and contains very low levels of salts and organic matter. At this stage, the water is already of potable quality.
The fourth barrier, and third stage of the NEWater production process, acts as safety precaution. UV disinfection is used to ensure that all organisms are inactivated and the purity of the product water guaranteed. With the addition of some alkaline chemicals to restore the pH balance, the NEWater is ready for use


http://www.pub.gov.sg/newater/NEWaterTech/PublishingImages/microfiltration.swf

Solat System

Websites with animations: http://www.kidsastronomy.com/solar_system.htm


From our small world we have gazed upon the cosmic ocean for thousands of years. Ancient astronomers observed points of light that appeared to move among the stars. They called these objects "planets," meaning wanderers, and named them after Roman deities—Jupiter, king of the gods; Mars, the god of war; Mercury, messenger of the gods; Venus, the goddes of love and beauty, and Saturn, father of Jupiter and god of agriculture. The stargazers also observed comets with sparkling tails, and meteors or shooting stars apparently falling from the sky. There are 8 planets revolving around the Sun. They are Mecury, Venus, Earth, Mars, Jupiter, Saturm,Uranus, Neptune


The Sun
Compared with the billions of other stars in the universe, the sun is unremarkable. But for Earth and the other planets that revolve around it, the sun is a powerful center of attention. It holds the solar system together; pours life-giving light, heat, and energy on Earth; and generates space weather. Without it, there will be no life on Earth.

The sun is a big star. At about 864,000 miles (1.4 million kilometers) wide, it could hold 109 planet Earths across its surface. If the sun were a hollow ball, more than a million Earths could stuff inside it. But the sun isn't hollow. It's filled with scorching hot gases that account for more than 99.8 percent of the total mass in the solar system. How hot? The temperature is about 10,000 degrees Fahrenheit (5,500 degrees Celsius) on the surface and more than 28 million degrees Fahrenheit (15.5 million Celsius) at the core. Most importantly, it is the ultimate source of energy!



Mercury
Mercury's orbit takes the small planet as close as 29 million miles (47 million kilometers) and as far as 43 million miles (70 million kilometers) from the sun. If one could stand on the scorching surface of Mercury when it is at its closest point to the sun, the sun would appear almost three times as large as it does when viewed from Earth.

Temperatures on Mercury's surface can reach 800 degrees Fahrenheit (430 degrees Celsius). Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to -280 degrees Fahrenheit (-170 degrees Celsius). Compared to Earth, whose minimum temperature is -87.8 degrees and maximum 57.8 degrees, it is definitely much higher.



Venus
Venus and Earth are similar in size, mass, density, composition, and distance from the sun. There, however, is where the similarities end.

Venus is covered by a thick, rapidly spinning atmosphere, creating a scorched world with temperatures hot enough to melt lead and a surface pressure 90 times that of Earth. Because of its proximity to Earth and the way its clouds reflect sunlight, Venus appears to be the brightest planet in the sky.



Mars
The RED PLANET
Mars is a small rocky body once thought to be very Earthlike. Like the other terrestrial planets—Mercury, Venus, and Earth—its surface has been changed by volcanism, impacts from other bodies, movements of its crust, and atmospheric effects such as dust storms.





Asteroid Belt

Asteroids are essentially chunks of rock that measure in size from a few feet to several miles in diameter. (Small asteroids are called meteoroids.) The largest asteroid, Ceres, is about 590 miles (950 kilometers) wide. Like most asteroids, it lies in the asteroid belt between Mars and Jupiter. Many astronomers believe the belt is primordial material that never glommed into a planet because of Jupiter's gravitational pull. Scientists always keep a wathchout for asteroids coming towards the earth as one small asteroids could damage a lot.

Electricity

Electricity (from the New Latin ēlectricus, "amber-like")is something essential in our everyday life.You need it to cook, charge your electrical appliances and anything you can think of.
Before starting on some facts about electricity, lets us discover on some of the history of electricty. Benjamin Franklin believed that electricity could be harnessed from lightning. In 1752, he devised an experiment to test his theory. Although details of the experiment remained a mystery to this day, Franklin originally wanted to test his theory atop a spire that was to be built on a church. As he thought about it in detail, he realized that his theory could be better tested by using a mobile kite, rather than a stationary spire. Franklin prepared the kite by tying a handkerchief to two crossed sticks of proper length. Extending vertically about a foot from the vertical stick was a wire. The apparatus was extended into the air by a length of string. Along the string of the apparatus was a metal key that would apparently conduct the electricity. Franklin hypothesized that the wire would draw 'electric fire' from the thunder clouds which would then be conducted through the apparatus and be contained in the key.

Based on this experiment that he had done, Franklin invented the first lightning rod. The lightning rod was built to attract electricity to his house. The lightning rods were attached to a system of bells that would ring throughout his house each time electricity had been attracted. The sparks produced would illuminate the house. Franklin's experiments helped the evolution of the common battery we use today. Walk around, can you see a metal rod on top of the houses? Without it, our lives could be in danger. Thanks to Benjamin Franklin, we are protected by his discovery.



Now for some fun. Electricity can be dangerous but there is one kind of electricity which is harmless. It is static electricty.
Try rubbing a balloon on your hair. After rubbing for some time, put it near your hair. What do you see? Can you see your hair rising?


Do you notice the same thing happening to you?
This is Static Electricity.It refers to the build up of electric charge on the surface of objects. The static charges remain on an object until they either bleed off to ground or are quickly neutralized by a discharge. Although charge exchange can happen whenever any two surfaces come into contact and separate, a static charge only remains when at least one of the surfaces has a high resistance to electrical flow (an electrical insulator). The effects of static electricity are familiar to most people because we can feel, hear, and even see the spark as the excess charge is neutralized when brought close to a large electrical conductor (for example, a path to ground), or a region with an excess charge of the opposite polarity (positive or negative). It feels just like a spider crawling on the surface of the skin!
Picture taken from google images.

Human Respiratory System

Before I talk about the parts of the respiratory system and some of its function, it will be betterfor us to first understand the reason for breathing.



Why do you need to breathe?
All the cells in your body require oxygen. Without it, they couldn't move, build, reproduce, and turn food into energy. In fact, without oxygen, you will die! So how do you get oxygen? From breathing in air which your blood circulates to all parts of the body.

How do you breathe?
You breathe with the help of your diaphragm and other muscles in your chest and abdomen. These muscles literally change the space and pressure inside your body to accomodate breathing. When your diaphragm pulls down, it not only leaves more space for the lungs to expand but also lowers the internal air pressure.The lower pressure inside the lung allow air to enter more quickly and easily. Outside, where the air pressure is greater, you suck in air in an inhale. The air then expands your lungs like a pair of balloons. When your diaphragm relaxes, the cavity inside your body gets smaller again. The prressure inside the lungs is greater now compared to the pressure outside of the body, so air flows more easily. With the help of your muscles squeeze your rib cage and your lungs begin to collapse as the air is pushed up and out your body in an exhale.

So, it all starts at the nose?
Yup. About 20 times a minute, you breathe in. When you do, you inhale air and pass it through your nasal passages where the air is filtered, heated, moistened and enters the back of the throat. The hairs in your nose trapd foreign particles and prevents them from entering the body. Interestingly enough, it's the esophagus or foodpipe which is located at the back of the throat and the windpipe for air which is located at the front. When we eat, a flap -- the epiglottis -- flops down to cover the windpipe so that food doesn't go down the windpipe.




Parts of the respiratory system
1. The nose hairs helps us to trap the dust particles so does the trachea. The mucus lines the cells of the trachea to trap inhaled foreign or dust particles which the then waft upwards towards the larynx and then the pharynx where it can either be swallowed into the stomach or expelled as phlegm.
2.The bronchus is a passage of airway in the respiratory tract that splits into 2 ways which conducts air into the lungs. No gas exchange takes place in this part of the lungs.
3.An alveolus (plural: alveoli, from Latin alveolus, "little cavity") is an structure that has the form of a hollow cavity. Found in the lung, the alveoli are respiratory sites of gas exchange with the blood. The oxygen rich blood here will be pumped to the heart and circulated round the body.

Sabbatical (Term 2 Science Eureka)

I opted for the Science Eureka sabbatical last term and the course was divided into Physics and Chemistry. I had done some experiments and these are the ones which are felt that are more important.


No.1
There are many different types of metals in the world. However, not all of them react in the same way.For example, bare iron (iron without any layering such as paint) rusts over some time into a disgusting brown colour. However, on the other hand, tin can stay shiny for a really long time. This is the fact because different metals have different reactivity. In the experiment that I had done, the experiment will be used to rank the metals order of reactivity.

Materials used:
Zinc Foils
Magnesium Ribbons
Iron Fillings
Copper Foils
Zinc Nitrate Solution
Copper(II)Sulfate
Magnesium Sulfate Solution
Iron (III)Sulfate Solution
Deionised water
3 test tubes
Sticky labels



Procedures
1.Fill the 3 different test-tubes with roughly 5cm cube of zinc nitrate solution
2.Add magnesium ribbon into one of the test-tubes and stir the mixture
3.Repeat step 3 with the other metals except zinc
4.Wash the 3 test-tubes thoroughly with tap water and then deionised water.
5.Repeat steps 1-5 with the remaining solutions of metal into its corresponding solution (ex. do not put copper into copper(II)nitrate)


After finishing the experiment, the results is as below.
The reactivity of the metals is( from lowest to the highest)
Copper, Iron, Zinc, Magnesium




Extra information


The reactivity series is very useful in our daily applications as it can be used in determining the method of the extraction of metals. For metals which of low reactivity (gold) they can be extracted on its own.

Reflections on Science Test

Scores
Term 1: 26/40
Term 2: 23/40
Term 3: 31.5/40




The reason why I can get an A1 this term is because of Mr Loh's hard work in helping those who are weaker in Science by giving extra lessons. Through each term tests, I have also gotten the grasp of the different ways to better remember Science facts instead of just memorizing without understanding the idea. I had to admit that I don't really appreciate Science in the beginning of the year because I found it really confusing and hard to remember.
However, after the low score of 23/40, I told myself that I had to work hard to improve may grades and better appreciate Science in order for me to learn more effectively. I had faced many difficulties but had managed to solve tham slowly step by step. Now, Science to be isn't the boring one but the subject which I liked the most. The EOY are coming and I hope I can score well with Mr Loh's comprehensive lessons and the techniques which I have learnt.