Sunday, May 31, 2009

Secondary School Mid-Year Holiday is a Nightmare!


Holiday (noun) is known as:
  • A period of time spent away from home for enjoyment and relaxation
  • (Often plural) Chiefly Brit & NZ a period in which a break is taken from work or studies for rest or recreation
  • A day on which work is suspended by law or custom, such as a bank holiday
From: http://www.thefreedictionary.com/Holiday
By Collins Essential English Dictionary 2nd Edition 2006 © HarperCollins Publishers 2004, 2006



From http://www.rd.ca/cms/images/image/extraburnout_230_y0u.jpg


School Assignment (noun) is defined as:
  • A school task performed by a student to satisfy the teacher
From: http://dictionary.reference.com/browse/school+assignment?qsrc=2446
By WordNet® 3.0, © 2006 by Princeton University.


Nightmare (noun) is known as:
  • A dream arousing feelings of intense fear, horror, and distress.
  • An event or experience that is intensely distressing.
  • A demon or spirit once thought to plague sleeping people.
From: http://www.answers.com/topic/nightmare



This coming Secondary School Mid-Year Holiday is from 29 May 2009 till 28 June 2009, almost the same as the Great Singapore Sales. It is supposed to be a period in which a break is taken from work or studies for the students. Students can take this opportunity to catch up with what they are weak in and have the rest of the time for rest or recreation activities.

Unfortunately this is not the case. The schools have been very enthusiastic in preparing and creating new lessons, worksheets, assignments, forums and quiz for almost every subject to be carried out by the students during the holiday period. Just to name a few subjects, English, Chemistry, Physics, Social Studies, E-Maths, A-Maths, Chinese, ..... For Chinese, they have to read two story books and complete the online assignments.


From http://genychina.com/wp-content/uploads/2009/02/technology-overload2.gif
During the school holiday, the students have to go back to take their English Oral Communication exam. Meanwhile they are told of a guide book, which cannot be found in any bookshop, to refer to. Even before the Oral exam has started, the schools have started posting articles, worksheets, assignments and lessons for the students to work on.

We are to suppose that the teachers would like to have their holidays and put the plight of their students to the back of their mind. The MOE has the slogan "Teach less, Learn more", which they intend to strictly adhere to. After all, a fully paid holiday is hard to come by, especially during this recession period. Brown harvests and green shoots have no value if there are iron bowls full of rice. Ah Kong's money seems to be easily planned and obtained.


Two headed tree ?
To have an idea of the amount of time required to carry out the tasks, they are tabulated for easy understanding and calculation.





















Estimated number of days available = 20
Time required per day = 224 ÷ 20 = 11.2 hours
This hour is 100% more than that of a normal 5.5hrs school day.

The student also has another 5 days of school related activities to attend.
It will be a very exhausting holiday.
When the school re-opens on 29 June 2009 there is a group of students selected to perform one week of official duties for the Asian Youth Game hosted in Singapore. During this one week, the rest of the students will attend classes normally whereas those on duty will be denied this opportunity. Instead they will have problems catching up with their studies. What the school is willing to do is just to keep the homework papers for them. Even that is also to be done by a school colleague living nearby. There is no plan on how to remedy the missed lessons. This is a very stressful situation for the student and this “crime” is allowed to be committed by the school which participated in the AYG.
Reference
Posted by at
Labels: , , , , , , , , , , , , , , , ,

Sunday, May 24, 2009

English Oral Communication - Conversation

Question:
"Even the best laid plans often fail". How true is this?
- Why might it be wise to make plans?
- Everyone would benefit if society were better organised. Do you agree?



Answer:
It started like this ....
Once upon a time, not so long ago, there was a person by the name called Ah Seng. Ah Seng lived in a Kampong at the country side. His ways of living were very simple. Whenever the weather permits, he plouged the land and planted something. Besides this, he took care of few hundreds of chickens, few dozens of pigs and a pool of ducks. He had to work every day because all the animals wanted to eat at least once daily. So Ah Seng had his hand full from morning till evening. He never really planned before hand. Neither did he needed to because he had a few brothers to fall back on if something unexpected occurred. When the feed stocks were low, he cycled to the immediate neighbourhood shop to order the replenishment. Water was plentiful, there were ever flowing streams and rivers around his farm. His harvest were abundant and he could even shared with his brothers and neighbours. Similarly they also shared theirs with him. Live was simple, healthy and easily manageable although having to work the whole day. Sleep were sweet and full.



Then one day while on his trip to the market to deliver the vegetables, Ah Seng met a girl. There was instant attraction and love. Very soon after, they had a lightning marriage. There was no family planning then, and Ah Seng had the privileged to have as many children as he liked. Within a short span of a decade, Ah Seng's family members increased by more than a dozen (enough to form a football team with reserves). He sent all his children to the nearby kampong schools. Some learned English, while others Chinese (Mandarin) together with the basic compulsory subjects like mathematics and science. With so many mouths to feed and so many activities to carry out, Ah Seng realised that he could no longer "happy and go lucky" any more. He needed to do some planning. And he planned to succeed in all he had set out to do. Ah Seng's natural resources were no longer adequate and he foresee many difficulties ahead. His farm was bursting with its limited capacity and ability to support the whole family. They really had to make ends meet. Sleep was no longer as sweet as before.



As if problems were not enough for Ah Seng, there were many new building projects around the kampong and most of the streams and rivers were blocked or redirected to elsewhere. Water soon was declared as Scare Commodity. Its cost escalated and was set to increase day by day. Many industrial estates popped up nearby and all the farm's crops were affected by the pollutions. Electrical power became a necessary item as increasing electrical items were being used. Traveling was more complicated due to increasing jams and more traffic lights. An one hour journey before had became a nightmare experience now. Cost of everything kept on increasing and live became more breathless. Vegetables and poultry were no longer as popular necessities as new products began to flood the markets. All the children were growing up and more were required for their education and living. Standard of living may have improved but Ah Seng began to have sleepless night. The cost of living was unbearable.



Fortunately the elder of the children were able to take up jobs to earn income to supplement the family expenditures. A few landed themselves in the fast-paced manufacturing industries, while others found jobs as project managers and engineers. Among other things, their tasks were to plan the execution of projects such that it can be completed within the tight schedules and within the given budgets. They have to fight for the best available resources and make use of them in the most efficient manner.



There are many types of plans. Operational, Full, Trial, Business, Survival, Apocalypse and Insurance.

Unfortunately there is no best laid plan, except for the movie, Best Laid Plans (1999) with Reese Witherspoon and Alessandro Nivola. This information can be obtained from the wikipedia website, http://en.wikipedia.org/wiki/Best_Laid_Plans.

No matter how carefully a project is planned, something may still go wrong with it. The saying is adapted from a line in “To a Mouse,” by Robert Burns: “The best laid schemes o’ mice an’ men / Gang aft a-gley.” The quotes is taken from The New Dictionary of Cultural Literacy, Third Edition. Edited by E.D. Hirsch, Jr., Joseph F. Kett, and James Trefil. Copyright © 2002 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.



The best laid plans often fail because:
  1. The world's business and operating environments are very dynamic. They are changing by the seconds and the related tasks of almost anything also change. That is why we have the term, Variation Order, which means modifications to the original plan are required.
  2. Live Styles are different. Earlier or 3rd world countries may not require plans to accomplish relatively straight forward tasks. Everybody is equipped and inbuilt with the ability to handle tasks up to a certain level of complexities. Simple one-task generally does not require sophisticated planning unlike complicated projects with many integrated tasks. Simple live styles only requires simple tasks to be performed. The more complex the lives, requires more integration of different services and hence time constraints and financial problems occur. It is impossible to expect help to arrive in the same sequence as needed.
  3. Occurrence of unexpected events or unforeseen circumstances. For example, pandemic H1N1 Flu or SARS may strike anytime and unexpectedly. The best laid plan may not take into consideration such emergencies or crisis. Therefore the projects or task will be seriously affected or even stopped.
  4. Unknown enemies. Terrorists are by now expected to strike at will. But when and how they will strike, nobody knows. They are still evolving and it is hard to implement solutions for this unknowns in the plan.
  5. Drastic and sudden economic condition changes. One moment we have recession, and boom the next. Any plan will have to be swiftly modified to fit the requirement, with respect to the demands of the economy. Sudden large quantity orders or many models for expedited tests could be problematic if the old plan is not discarded and new one put in place.
  6. Direct retrenchment or cutting related staffs. product transfer from one country to another, is often accompanied by retrenchment or some other form of staff deployment. With a leaner staff force, delay in services and operations are inevitable. What is specified in the previous plan is no longer valid and failure is imminent if continue to proceed as originally planned.



Why it might be wise to make plans
  1. Planning enable us, up to a certain extent, to be able to see where we are going. If we have all the information on hand, it may be possible to predict what is going to happen, thus enabling us to take appropriate action and make more realistic plan. If we plan not to plan, then it may be wiser to stop everything altogether.
  2. A proper plan would instill others to have confidence in us. The better the plan is, the better the success rate and hence more dollar and cents profit could be a reality.
  3. When appropriate and adequate planning is being done, there will be less panic when the crisis eventually occur.
  4. Future generation may benefit from what is being done. A better plan may be produced to overcome the problems and making the world a better place to live in.


Everyone would benefit if society were better organised.
Agree:
  1. Less effort required to get something done. Instead of having to go through many layers of red tapes. A all-in-one system can certainly minimised the time wasted for queuing, multiple forms filling and hunting for hard-copied documents.
  2. There will be more efficient use of resources. For example, an infrad camera can replace many manual temperature taking operators at the hospital.
  3. More accurate and faster process. For example, vistors' temperature can be measured more accurately and quickly, before allowing them to proceed to the wards to visit the patients.
  4. Faster in tracking down of the affected persons. Those infected can be prevented from spreading further.


Everyone would benefit if society were better organised.
Disagree:
  1. The more organised, the more restrictions will be imposed. This could inconvenient people in the society instead of benefiting them.
  2. More restriction means less or no freedom to perform a task by some other methods other than the organised way. This could retard or prevent the development of better solutions to the problem.
  3. Human errors may occur and escape detection if a single method is used to accomplish the task. There is no counter checking available to confirm the reliability of the method used.


Reference
Posted by at
Labels: , , , , ,

Monday, May 4, 2009

Chemistry - Covalent and Metallic Bonding (Part 1)

The Chemistry question is,
Silicon carbide, SiC, has a very high melting point and a structure like that of diamond.

(a) Silicon carbide is made by heating carbon with silicon dioxide, SiO2, at high temperature. The other product of the reaction is carbon monoxide, CO.
Construct a balanced equation for the reaction.

(b)
i) Draw a diagram to show the possible structure of silicon carbide. Use this structure to suggest why silicon carbide has a very high melting point.
ii) Suggest two other physical properties of silicon carbide.


Photo is obtained from http://en.wikipedia.org/wiki/File:SiC_p1390066.jpg

Solution:


(b) i) Diagram of silicon carbide possible structure



The structure is in a tetrahedral shape, which is a macromolecular compound. Macromolecular compound has high melting point.

ii) They are very hard and do not conduct electricity.


Reference
Posted by at
Labels: , , , , , , , ,

Sunday, May 3, 2009

Perodic Table of Pokemons

Although I am not yet an ardent fan or lover of pokemons, this periodic table caught my attention. The creator of this master pieces must be a pokemons lover.

The "Chemical" characteristics and properties also reveal the interest in chemistry. Studying chemistry is going to be fun! The periodic contents are still intact with the atomic mass, element names, element symbols and proton (atomic) numbers.

I like especially the short descriptions of each "Element" which could be the characteristic of the pokemon in the picture. However we need to interpret the background colouring. In the normal periodic table the colour indicates metal / non-metal / gas / metalloid / halogen (form salts called halides) / others properties of the elements. The colour of the edges of each cells takes over this function.

For example edge colour,
light blue for metal,
dark red for non-metal,
purple for elements with both metal and non-metal property (metalloid), and
pink for noble gas.

Interpretion of background colour
Red for alkali metal,
Light green for alkaline earth metal,
light blue for halogen,
purple for noble gas,
white background with light blue edges for transition elements,
white background with purple edges for metalloid (element with both metal and non-metal property),
white background with red edges for non-metal,
light brown for lanthanides and
light yellow for actinides.

A rare, precious and creative pieces of work. Full of initiative with a strong sense of humour.

Such tremendous amount of efforts certainly deserve global appreciation from young and old alike.

A timless and classical piece of beautiful art waiting for Nobel prize to be awarded.


Please click on it to see the other pokemons.
Extracted from http://aleptu.com/images/2009/03/periodic_table_of_pokemon.jpg
The table has about 112 pokemons out of the 500 some times back. I still haven't find Pikachu, the only pokemon I know so far.


A smaller version of the same table.


The Periodic Table of Elements
The Periodic Table is a list of elements arranged in order of their increasing proton (atomic) numbers. The Periodic Table divides the elements into periods and groups.

A period is a horizontal row of elements and a group is a vertical column of elements.

Periods
The Periodic Table consists of 7 periods of elements, numbered 1 to 7. The periods run horizontally from left to right. Each element in a period has a proton number. This number increases by 1 as we move across to the right. For example, in Period 1, hydrogen has a proton number of 1 and helium which is to the right has a proton number of 2.

Groups
The Periodic Table consists of 8 groups of elements, numbered 1 to 0. They run vertically from top to bottom. Group 0 is sometimes called Group VIII.


The Periodic Table from http://media-2.web.britannica.com/eb-media/45/7445-004-6D310733.gif

Transition Elements
The block of metals between Group II and III is known as the transition elements.

Metallic and Non-metallic Characteristics
Metals are grouped on the left-hand side of each period.
Non-metals are grouped on the right-hand side.
Due to the change from metal to non-metal across a period, there is also a change in the properties of the elements.

GROUP I Elements - Alkali Metals
  • Alkali metals are soft.
  • They can be cut easily.
  • It has shiny and silvery surface but rapidly tarnishes in air.
  • They are called alkali metal because they react easily with water to form alkalis.
  • They have low melting and boiling points. Lithium (Li), sodium (Na) and potassium (K) are the first three elements in the group.
  • Alkali metals have low density and float on water.
  • The alkali metals are reactive metals and must be stored in oil to prevent reaction with air and water.
  • Alkali metal are powerful reducing agents. They have one electron in their outer shell and thus can readily lose it to behave as powerful reducing agent in all reactions.
  • Compounds of the alkali metals are ionic, soluble in water, and have similar chemical formula.


GROUP I, II and III Elements - Metals
  • Their atoms lose electrons to form positive ions.
  • The charge of the ion is the same as the group number of the element forming it.

GROUP IV and V Elements
They are less likely to form ions.
  • They share electrons to form covalent bonds
  • Have maximun oxidation state that is the same as the group number of the element

GROUP VI and VII Elements
  • They are non-metals
  • They tends to gain electrons and form negative ions

GROUP VII Elements - Halogens
The elements in Group VII of the Periodic Table are called Halogens. The elements in the group are flourine (F), chlorine (Cl), bromine (Br), iodine (I) and astatine (At).
  • Ther halogens are non-metals.
  • They exist as diatomic covalent molecules.
  • The halogens have low melting and boiling points.
  • They are coloured.
  • Halogens are reactive non-metals. The valence shell of each halogen contains seven valence electrons. They only need one more electron to achieve a stable noble gas structure.
  • Halogens react with most metals to form salts called halides.

GROUP 0 or Group VIII Elements - Noble Gases
The elements in Group 0 or Group VIII of the Periodic Table are called noble gases. The elements in the group are least reactive in the Periodic Table.
  • They have stable electronic configuration
  • They do not form compounds

Helium has 2 valence electrons and the rest have 8. Their full electronic structures make the noble gases unreactive.
This group are also known as inert gases (because they are unreactive) or rare gases (because less than 1% of the air is made up of these gases).

The noble gases are:
  • monoatomic elements
  • colourless gases at room temperature (r.t.p)
  • low melting and boiling point that increases on going down the group
  • insoluble in water
  • unreactive
Noble gases do not react to form compounds because their atoms have full outer shells of electrons.They do not lose,gain or share electrons, hence they are unreactive.
Nobel gases such as argon are used to fill light bulbs. They provide an inert atmosphere which prevents the filament from oxidation.

The current standard table contains 117 elements as of March 10, 2009.
.

Reference
Posted by at
Labels: , , , , , , , , , , , ,

Saturday, May 2, 2009

Chemistry - The Mole

The Chemistry question is,
An organic compound contains 12.8% carbon, 2.1% hydrogen and 85.1% bromine by mass. Its relative molecular mass is 188.
(a) Calculate the empirical formula
(b) Deduce its molecular formula



Extracted from http://www.fordhamprep.org/gcurran/sho/sho/images/images/science/miscella/aspirin.gif


Solution:
The percentage of each element is directly proportional to its mass in grams. That is, the mass of each element in 100g of the compound is equal to its percentage in the compound.

The relative atomic mass of each element can be found from the periodic table.


Extracted from http://aleptu.com/images/2009/03/periodic_table_of_pokemon.jpg
Humorous Periodic Table with Pokemons for the elements - very educational and creative. Very rare and precious treats for all Pokemon lovers.

Extracted from http://www.lbl.gov/abc/marsh-nuclei/images/table_sig.jpg
Serious Periodic Table with atomic mass, states and metal/non-metal/gas/others properties for the elements - very educational and professional.

Knowing the mass and relative atomic mass of each element, the number of moles of the element can be calculated by using the formula:

Number of moles of an element




From the question above, the Mass of carbon is 12.8g (in 100g of the compound)
From the periodic table, Relative atomic mass of carbon, Ar, is 12.

Therefore the Number of moles of carbon



The number of moles of the hydrogen and bromine can be calculated using the same method.

The Molar ratio is also calculated by taking the number of moles of each element and divide by the smallest mole number. In this case the smallest mole number is 1.

The results are tabulated as follow.


Finding the number of moles of bromine, carbon and hydrogen in the compound


(a) The empirical formula

The empirical formula of a compound shows
i) The types of elements present in it,
ii) The simplest ratio of the different types of atoms in it.

The empirical formula of the compound is thus,

(Answer)

(b) The molecular formula

The molecular formula is the formula that shows the exact number of atoms of each element in a molecule.
The molecular formula of a compound is a multiple of its empirical formula.

If the empirical formula

then the molecular formula

n can be found using the equation:




Given that the relative molecular mass of the compound is 188

Therefore, n



The empirical formula of the compound is

Then the molecular formula

(Answer)


Extracted from http://img.photobucket.com/albums/v199/crissytrewin/PeriodicTable.jpg
Humorous Periodic Table with cartoons for the elements - very educational as well as entertaining.


Extracted from http://www.bpc.edu/mathscience/chemistry/images/periodic_table_of_elements.jpg
Serious black & white Periodic Table. It may not provide the metal/non-metal/gas property of the elements but is handy and less stressful to work with, when lesser amount of information are required.

 Reference
Posted by at
Labels: , , , , , , ,
Subscribe to: Posts (Atom)