Chemistry Courses Online

The “Reasoning in Biological and Physical Sciences” section contains questions on Biology, Chemistry and Physics. Equal weightage is given to Biology and Chemistry as each of them comprise of 40% of GAMSAT Section III. Questions on Physical Sciences comprise of only 20% of this section. Thus, to get the qualifying marks in GAMSAT, aspirants not only have to answer the chemistry questions, but also have to answer them correctly.

VALENCE ELECTRON CONFIGURATIONS AND GROUPS.
Now to a more involved subject, whereby group number is related to valence electron configuration. As mentioned earlier, the principal energy levels are divided into sublevels, which are equal in number to the principal energy level number: principal energy level 1 has one sublevel, level 2 has two sublevels, and so on. As one might expect, with an increase in principal energy levels and sub-levels, there are increases in the complexity of the orbitals.

Though atoms differ, subatomic particles do not. There is no such thing, for instance, as a “hydrogen proton”—otherwise, these subatomic particles, and not atoms, would constitute the basic units of an element. Given the unvarying mass of subatomic particles, combined with the fact that the neutron only weighs 0.16% more than a proton, the established value of 1 amu provides a convenient means of comparing mass. This is particularly useful in light of the large numbers of isotopes—and hence of varying figures for mass—that many elements have.

CONCEPT
In virtually every chemistry classroom on the planet, there is a chart known as the periodic table of elements. The boxes would form a rectangle, 18 across and 7 deep, but there are gaps in the rectangle, particularly along the top. To further complicate matters, two rows of boxes are shown along the bottom, separated from one another and from the rest of the table. Even when one begins to appreciate all the information contained in these boxes, the periodic table might appear to be a mere chart, rather than what it really is: one of the most sophisticated and usable means ever designed for representing complex interactions between the building blocks of matter.

CONCEPT
Reactions are the “verbs” of chemistry—the activity that chemists study. Many reactions move to their conclusion and then stop, meaning that the reactants have been completely transformed into products, with no means of returning to their original state. In some cases, the reaction truly is irreversible, as for instance when combustion changes both the physical and chemical properties of a substance. There are plenty of other circumstances, however, in which a reverse reaction is not only possible but an ongoing process, as the products of the first reaction become the reactants in a second one. This dynamic state, in which the concentrations of reactants and products remains constant, is referred to as equilibrium. It is possible to predict the behavior of substances in equilibrium through the use of certain laws, which are applied in industries seeking to lower the costs of producing specific chemicals. Equilibrium is also useful in understanding processes that preserve—or potentially threaten—human health.

What follows are the names and formulas for the first eight normal, or unbranched, alkanes. Note that the first four of these received common names before their structures were known; from C 5 onward, however, they were given names with Greek roots indicating the number of carbon atoms (e.g., octane, a reference to “eight.”)
The reader will undoubtedly notice a number of familiar names on this list. The first four, being the lowest in molecular mass, are gases at room temperature, while the heavier ones are oily liquids. Alkanes even heavier than those on this list tend to be waxy solids, an example being paraffin wax, for making candles. It should be noted that from butane on up, the alkanes have numerous structural isomers, depending on whether they are straight or branched, and these isomers have differing chemical properties.
Branched alkanes are named by indicating the branch attached to the principal chain. Branches, known as substituents, are named by taking the name of an alkane and replacing the suffix with yl—for example, methyl, ethyl, and so on. The general term for an alkane which functions as a substituent is alkyl.

CONCEPT
There was once a time when chemists thought “organic” referred only to things that were living, and that life was the result of a spiritual “life force.” While there is nothing wrong with viewing life as having a spiritual component, spiritual matters are simply outside the realm of science, and to mix up the two is as silly as using mathematics to explain love (or vice versa). Not everything that has carbon is living, nor are all the areas studied in organic chemistry—the branch of chemistry devoted to the study of carbon and its compounds—always concerned with living things. Organic chemistry addresses an array of subjects as vast as the number of possible compounds that can be made by strings of carbon atoms. We can thank organic chemistry for much of what makes life easier in the modern age: fuel for cars, for instance, or the plastics found in many of the products used in an average day.

1. Name that element!

2, Which of the following elements is found in the same group as zinc (group 12)?

A Hafnium (Hf)

B Tin (Sn)

C Iodine (I)

D Cadmium (Cd)

3. Which of the following elements is a transition metal?

A Calcium (Ca)

B Astatine (At)

C Hassium (Hs)

D Radon (Rn)

4. An amalgam is

A a combination of the mystery element and a metal.

B the negative end of a battery.

C a mineral.

D all of the above.

Chemistry: the central science
The real importance of Chemistry is that it serves as the interface to practically all of the other sciences, as well as to many other areas of human endeavor. For this reason, Chemistry is often said (at least by chemists!) to be the “central science”.

Chemistry can be “central” in a much more personal way: with a solid background in Chemistry, you will find it far easier to migrate into other fields as your interests develop.

Usually a leader in this field, academia has chosen to stay out of this new method of communication so far. So the phenomenon known as the Webinar has been only utilized by a small number of corporations.
While the potential applications of this technology are endless, the place we will focus today is on Internet tutoring. Picture this scenario: a troubled college student cannot get the help she needs with organic chemistry on her college campus.