## Testing Times (part 1)

Tests are everywhere. Tests are more than “just” a part of school. You will be tested throughout your life – anytime somebody wants to know whether you know what you should know – or how well you know what you know – there will be a test. This could be your teacher testing what you have learnt, your boss checking to see if you can do the job right, or anybody who has responsibility for or authority over you. This is not a reason to be worried.If tests are going to be an ongoing part of your future, you have to learn how to deal with them. Here’s an example of what not to do: `[kml_flashembed movie="http://www.youtube.com/v/m-W3D5saBFk" width="425" height="350" wmode="transparent" /]`

The most important thing to remember is that a test is more than an assessment of what you know, it is an opportunity to learn in itself. If you treat a test as a learning opportunity it can make you far more successful in the assessment! So what’s the first step in this process? Easy:

The test belongs to you. This is YOUR test, not your teacher’s, not your parents’. YOU OWN THIS TEST.

What does this mean? Well, if it is your test, you get to decide how to do it. You can start with choice – you get to choose where to start. You don’t have to start with question 1, or section A. You can start at the end, you can start with the material you are most confident with, you can start with the questions with the most marks – it is your choice!

You own the test. Act like it. Make it yours. It’s not about luck, its about using the opportunity. Plan your attack, and crush that test like an empty coke can! (Answers to the Practice Probability Test are here!)

See you in class!

Explore posts in the same categories: General Science, Mathematics, Philosophy, Physics

### 7 Comments on “Testing Times (part 1)”

1. Kern Says:

Hi all,

The number of electrons in the outermost shell tells us the valence of an atom. This is why the outer shell of an atom is called the valence shell while the electrons contained in this shell are called valence electrons. The valence of an atom determines its ability to gain or lose an electron, which in turn determines the chemical and electrical properties of the atom. An atom that is lacking only one or two electrons from its outer shell will easily gain electrons to complete its shell, but a large amount of energy is required to free any of its electrons. An atom having a relatively small number of electrons in its outer shell in comparison to the number of electrons required to fill the shell will easily lose these valence electrons. The valence shell always refers to the outermost shell.

Why do some elements like silver have 2 valancies?(if interested to know complicated stuff!)

The elements having d-orbital as penultimate orbital and the outermost s-orbital, like transition metals, show variable valency.
This is because they have unfilled d-orbital but filled s-orbital.

For example Iron (Fe) Atomic no 26, so 26 electrons to be filled in different orbital. So the electronic configuration is
(1s)2 (2s)2 (2p)6 (3s)2 (3p)6 (4s)2 (3d)6 this is the way of filling of electrons according to aufbau’s principle. But the exact arrangement is (1s)2 (2s)2 (2p)6 (3s)2 (3p)6 (3d)6 (4s)2
So Iron can lose two electrons from the outermost 4s subshell to show a valency of two. Then it can lose another electron from the 3d subshell (penultimate) two show a valency of three. When it shows the valency of two the electron configuration is (1s)2 (2s)2 (2p)6 (3s)2 (3p)6 (3d)6 (4s)0
When it shows the valency of two the electron configuration is (1s)2 (2s)2 (2p)6 (3s)2 (3p)6 (3d)5 (4s)0
And the +3 valence state is stabler than the +2 valence state, because the d-orbital contains 5 electrons (halffilled). As you know fully filled and exactly half filled orbitals are more stable than the orbitals having different no of electrons, i.e. less than half filled and more than half filled but not fully filled.

The transition metals show variable oxidation states. like manganese, Mn shows +2, +4, +6, +7 oxidation states.

Note: You might not know the shells which are talked about above and you don’t need to as these are not in the year 10 course but if you want to know go here http://en.wikipedia.org/wiki/Electron_configuration or you can also ask Mr.G

In short summary, some elements have more valencies due to their electronic configuration.

Where I copy pasted all this information from?… http://in.answers.yahoo.com/question/index?qid=20070531215940AA9yN2o

2. Lynette Says:

Kern: What is an orbital, and what on earth is Aufbau’s Principle?

3. Lynette Says:

I DON’T UNDERSTAAAAAND!!!!!!!!

Aufbau’s Principle = that thing about subshells.
Orbital = ?

Silver = not a group two element at all. It is a transitional element which has varying valencies. Silver (I) has a valency of 1+, Silver (II) has a valency of 2+ and so on, I think. The same goes for Iron (I think Kern said that?) Transitional elements don’t belong to groups and have an incomplete inner electron shell (is that ‘s’ or is it ‘K’?)

and… what?

When are we expected to know all of this? *confused*

4. Kern Says:

Hi Lynette,

Aufbau principle is a rule for filling orbitals

http://en.wikipedia.org/wiki/Aufbau_principle

Orbital – It’s where an atom keeps its electrons…..shell….

You’re not expected to learn anything from above other than what we did in class. It’s just an extra thing for people who are interested to know why some elements have more than 1 valency.

5. Lynette Says:

So an orbital is a subshell? Yeah I googled Aufbau’s principle.
I still don’t understand it, but thanks anyway.
😦

6. Kern Says:

Why the electron shells are called s, p ,d, f??

The orbital names s, p, d, and f stand for names given to groups of lines in the spectra of the alkali metals. These line groups are called sharp, principal, diffuse, and fundamental.

The orbital letters are associated with the angular momentum quantum number, which is assigned an integer value from 0 to 3. s correlates to 0, p = 1, d = 2, and f = 3.The angular momentum quantum number can be used to give the shapes of the electronic orbitals. s orbitals are spherical; p orbitals are polar. It may be simpler to think of these two letters in terms of orbital shapes (d and f aren’t described as readily).

The electron configuration of an atom denotes the distribution of electrons among available shells. The standard notation lists the subshell symbols, one after another. The number of electrons contained in each subshell is stated explicitly. For example, the electron configuration of beryllium, with an atomic (and electron) number of 4, is 1s22s2 or [He]2s2.