Practice, Practice, Practice?

I feel that too much emphasis has been placed on practice exercises rather than theory. When I say practical exercises, I do not mean practical sessions, but homework and past-year tests. If this were a subject such as mathematics, I would not question this method, but for science, it is my opinion that a lot is based on knowing your facts. Of course, for most subjects, some amount of practice is still needed on top of the theory aspect of learning. However, I believe that for science, this amount should be kept to a minimum. Unlike mathematics, for science there is no significant gain for the same amount of practice. As such, I feel that the valuable class time that is spent on going thorough worksheets is better spent going through important facts that have to be deeply ingrained in the minds of students.

An Expression of Opinion

In my opinion, the general progress and quality of the lessons are commendable. The teacher is clearly making a huge effort in a bid to improve the standards of the lessons and make it interesting for the students. Pertaining to the latter, I feel that the teacher's efforts have only partially succeeded. While it is a good try, I hope that the teacher is able to find a method to spice up the lessons, as this is crucial to maintaining the attention of students, which will directly affect their grades. While there is clearly room for improvement in this area, the fact remains that the lesson is able to hold the interest of the bulk of the students most of the time. I hope that the teacher will do something to address this issue.

Reflections on Term 1

Over the course of the first term of a year, I feel that I have learnt quite a lot for a single term. We have covered new topics that have never been touched on in much detail before, and I realise I enjoy many of these new topics. While this is the merely the beginning of the year, the workload is not at all light. In fact, within a couple of months' time, the workload is increasing by the week and the work has been piling up. This is, of course, to be expected, and I am still coping reasonably well. This is a surmountable problem that most students face all the time, so it is not a cause for undue concern for me. There is a lot to be done this term, and for the rest of the year. Overall, though, this has been a good start to the new year.

Covalent Bonding - A Further Study

In the process of studying covalent compounds, most students, myself included, have undoubtedly wondered, "Why do elements share electrons? Why wouldn’t atoms just gain electrons from another atom, as happens when ionic compounds are formed? Why should it be any different?"

Well, the reason that non-metals have to share electrons with each other is directly related to electronegativity. To put it simply, electronegativity is a measure of how much an element pulls electrons away from other elements it is bonded to. Generally, metals have very low electronegativities (meaning they don’t really try to gain electrons) while non-metals have high electronegativities (meaning they have a strong need/urge to gain electrons). The reason for this trend is the octet rule, which states that all elements strive to achieve the same number of electrons as the nearest noble gas, due to noble gases being far more stable. When metals bond with non-metals, the result is fairly obvious to see. Ionic compounds will be formed because the metal atoms have an excess of electrons and will easily lose them to non-metals that require electrons.

It’s altogether a whole new ball game, however, when two non-metals bond with each other. Instead of simply having one element give electrons to another, we end up with a situation whereby we have two elements with about the same electronegativity. As a result, neither element is able to gain electrons from the other. As a result, if either of them aims to attain noble gas structure, they end up having to share electrons rather than transfer them.

Covalent Compounds

Covalent compounds are compounds in which the atoms that are bonded share electrons with each other instead of transferring electrons from one to the other. While ionic compounds are usually formed when metals bond with non-metals, covalent compounds are formed when two non-metals bond with each other.

Primary General Properties (Exceptions always exist):

1) Covalent compounds generally have much lower melting and boiling points than ionic compounds.

2) Covalent compounds are soft and squishy (compared to ionic compounds, anyway).

3) Covalent compounds tend to be more flammable than ionic compounds.

4) Covalent compounds don't conduct electricity in water.

5) Covalent compounds aren't usually very soluble in water.

Can animals sense natural disasters?

Can animals sense natural disasters in advance? I've come across mention of this phenomena many times already - in books, movies and even in documentaries. In movies, it is sometimes very subtly hinted at, or over-dramaticised. This is a very curious occurrence! I've been wondering how can such a thing occur? We humans are supposed to be the most intelligent race that has ever walked the face of the earth, so how is it that animals can sense what we do not? Having gone through extensive research and thinking on the topic of my own volition, having built up an interest in this, I have arrived at the following conclusion: Is it possible that after millenia of "cultured" living in the rapidly modernising world, the senses that all have been born with have been lost to mankind in the tides of time. It may be that as a race, we are no longer born with this ability to sense natural disasters, or perhaps we are no longer being born with this sense. In the midst of pondering this matter, something has occurred to me - Is this the widely talked-about "sixth sense"?

The following is one of the articles I came across in my research on this topic. It is sourced from this government site:

*U.S. Department of the Interior, U.S. Geological Survey-Earthquake Hazards Program
URL: http://earthquake.usgs.gov/

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On December 26, 2004, an earthquake along the floor of the Indian Ocean was responsible for a tsunami that claimed the lives of thousands of people in Asia and East Africa. In the midst of all the destruction, wildlife officials at Sri Lanka's Yala National Park have reported no mass animal deaths. Yala National Park is a wildlife reserve populated by hundreds of wild animals including elephants, leopards, and monkeys. Researchers believe that these animals were able to sense the danger long before humans.
Can Animals Sense Natural Disasters?

Animals have keen senses that help them avoid predators or locate prey. It is thought that these senses might also help them detect pending disasters. Several countries have conducted research on the detection of earthquakes by animals. There are two theories as to how animals may be able to detect earthquakes. One theory is that animals sense the earth's vibrations. Another is that they can detect changes in the air or gases released by the earth. There has been no conclusive evidence as to how animals may be able to sense earthquakes. Some researchers believe the animals at Yala National Park were able to detect the earthquake and move to higher ground before the tsunami hit, causing massive waves and flooding.

Other researchers are skeptical about using animals as earthquake and natural disaster detectors. They site the difficulty of developing a controlled study that can connect a specific animal behavior with an earthquake occurrence. The United States Geological Survey (USGS) officially states: *Changes in animal behavior cannot be used to predict earthquakes. Even though there have been documented cases of unusual animal behavior prior to earthquakes, a reproducible connection between a specific behavior and the occurrence of an earthquake has not been made. Because of their finely tuned senses, animals can often feel the earthquake at its earliest stages before the humans around it can. This feeds the myth that the animal knew the earthquake was coming. But animals also change their behavior for many reasons, and given that an earthquake can shake millions of people, it is likely that a few of their pets will, by chance, be acting strangely before an earthquake.

Although scientists disagree as to whether animal behavior can be used to predict earthquakes and natural disasters, they all agree that it is possible for animals to sense changes in the environment before humans. Researchers around the world are continuing to study animal behavior and earthquakes. It is hoped that these studies will help to aid earthquake predictions.

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If after reading this, you now find yourself interested and curious about this, why don't you go ahead and Google the topic? I'm sure you shall find a lot of interesting information on this, and you can arrive at a conclusion of your own, be it the same or different from mine!

Term 1 Test Reflections

The first test of the year... I think I didn't do too well. The problem seems to be that I am unfamiliar with the new topics that we have just begun to learn this year. We have been doing mainly chemistry this term, specifically looking at the following topics:

-Equation Writing

-Acids, Bases and Salts

-Periodic Table

-Atomic Structure

-Chemical Bonding

...And that's about it! I believe my weaknesses lie in these topics:

-Equation Writing

-Acids, Bases and Salts

I just cannot seem to get these topics right! As for the other topics, while the periodic table would have been a tough one, luckily we were allowed the use of the periodic table during the test! What a relief! A little work was still needed though, as should be the case. Atomic structure and chemical bonding gave me some trouble when revising, as I especially disliked drawing all those diagrams, but they turned out to be fine in the test.