Quality Bonding Time

It's time for some... "Quality Bonding Time "!
And no that does not mean we are going to bond over a campfire with s'mores... (which quite frankly sounds preferable).

 

Instead, you, the mystery man/woman, looking at this post can read this blog regarding...

Chemical Bonding

... and bond with yourself.

Chemical Bonding occurs, in this universe, although not necessarily in parallel universes, in three different ways.


NUMBA 1: IONIC BONDING


This type of bond occurs between a metal and a non-metal.
The metal (positively charged) will give away some or all of its valence electrons to the non-metal (negatively charged) to create an EPIC neutral ionic compound between two or more atoms.



NUMBA 2: NON-POLAR COVALENT BONDING

Aka COVALENT BONDING will occur between two non-metals (negatively charged) and funnily enough usually between the same non-metals.  See what I just did there? You're bonding with yourself by reading this blog and the non-metals are also (often) bonding by themselves. MIND = BLOWN.  The two non-metals will come together to share some or all of their valence electrons to create an equally EPIC non-polar covalent compound between two or more atoms.


NUMBA 3: POLAR COVALENT BONDING

This bonding is sooooo similar to "NUMBA 2" but not quite... The only difference is that one side of the covalent bond is getting more of the action.  Meaning that the more electronegative / non-metalish atom will still share valence electrons with the less electronegative / non-metalish atom; however the electrons "like" non-metals better (apparently) and will therefore spend more of their time there.


DID YOU KNOW THAT???
A. I just made a Bill Nye - the Science Guy reference.
I. IONIC compounds have a very high melting point cause of their exceedingly mighty bonds
C. COVALENT compounds also have a very high melting point cause of their exceedingly mighty bonds but have a lower melting point because of the weaker bonds that hold multiple covalent compounds together.

Calculating Electronegativity Difference

Elements in the PT (Periodic Table) have specific electronegativities. Not sure what unobtanium's is though, probably because it's un-obtain-able. LOL.

Anywho, to calcuate the ELECTRONEGATIVITY DIFFERENCE (ENeg Diff.) use the simple formula:

Energy difference = Electronegativity 1 - Electronegativity 2.

Which will, ergo, tell you what kind of what kind of chemical bond is formed.  Sorry for blowing your mind, again!

SITUATION 1: The ENeg Diif. is less than 0.5 - which means the compound will form a Covalent Bond!

SITUATION 2: The ENeg Diff. is greater than or equal to 0.5 and less than or equal to 1.8 - which means the compound will form a Polar Covalent Bond!

SITUATION 3: The ENeg Diff. is greater than 1.8 - which means the compound will form an Ionic Bond!

"DUUUUUUDE, NARLY, DUUUUDE" - you must be saying.

BAZINGA!

If you're feelin' G and want to learn about bonds watch this vid:

Now, a quick recap on Lewis Diagrams. I know we learned this all last year, but how about a couple examples and diagrams, ok?

This is one of the most common, H2O, but something to notice is that it is bended. Hmmm....

You are probably thinking, "Oh great Chemistry King! How will I know if it is bended or not?"
'Well, young grasshopper, you'll just have to memorize this one." Words of wisdom.




Here's CO2 (yes. "X" is ok too):

Now, if all of that grade ten curriculum isn't coming flooding back to you, check out this video. She makes it look SO simple.

You go gurl. Like a boss.

What will make you richer, Ionic Bonds or Covalent Bonds? hehe

There are two kinds of chemical bonding:

Ionic Bonding and Covalent Bonding.

Ionic Bonding involves the bonding between a metal and a non-metal (or an element with a positive charge, and an element with a negative charge).  The positively charged metals will give away a certain number of electrons to negatively charged non-metals because of the strong attraction of the non-metal.

Observe and Learn:




Where as...

Covalent Bonding involves the bonding between non-metals and non-metals.  In this instance, the chemically bonding non-metals will share a certain number of valence electrons (electrons in the outer-most shell).




But remember kids, if in doubt google it out.

And voila, you may have found:

"All About Covalent Compounds" http://misterguch.brinkster.net/covalentcompounds.html

"All About Ionic Compounds" http://misterguch.brinkster.net/ionic.html

or better yet...

"Ionic and covalent bonding animation"

What's Trending on the Periodic Table these Days?

Fortunately, the many different trends of the periodic table are very unlike fashion trends which vary from year to year and season to season (which would make it exceedingly difficult for students).  Instead, periodic trends ironically tend not to trend (as in internet fads) and are certainly not very trendy.

However, they can certainly be somewhat interesting!

Ionization Energy: The amount of required energy to remove an electron from an atom (to create an ion).

Ionization energy will increase as it moves right across a period (row) because there are more protons which cause a greater pull on the electrons.  And it will decrease as it moves down a group (column) because the protons are farther away from the electrons energy shells and because of the shielding effect, or the repelling of electrons.

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Atomic Radius: Quite simply the radius of an atom.

The atomic radius will decrease as you moves right across a period because of the increased attraction of protons.  But it will increase as you move down a group because each energy shell results in a larger distance to the nucleus.

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                                                                                 n

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Electra-negativity: Is an element's property as a non-metal to take in an electron; elements are more likely to do this when they have a negative charge. 

Electra-negativity tends to increase as you move right across a period because non-metals are located on the right side of the periodic table.  But it will decrease as you move down a group. Aside - chances are if it increases as you move right then it will decrease as you move down and vice versa!!!

                                                                                      y                                                                                                                          

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Density is mass per unit volume.

Give this a try yourself! Remember what density means and what causes atoms to become denser!

Here are some additional trends you may want to remember:

Atomic Size: It decreases as you move right across a period but increases as you move down a group.

Reactivity: It is lowest in the middle of the PT (periodic table and increases left downwards, and righ upwards.

The Melting point incrases as it approaches the centre of the PT.

Don't forget to try the...

Dynamic Perioidic Table - Ms. Chen approved

(it will help you experiment and learn different trends) : http://www.ptable.com/

Predicting the Number of Valence Electrons

Valence Electrons are all of the electrons which take part in reactions. They are also known as "Reactable Electrons". They are located in the outermost open shell of an atom. The highest  shell. In other words, if you had 6s24f145d106p2, you would only have 4 valence electrons, since you would only count the ones in the 6th orbital.


Here are some new terms to learn:
Open Shell: Shell containing less than the maximum number of electrons.
Closed Shell: Shell that contains exactly the maximum number of electrons.


So, in a nutshell (so punny, I know), valence electrons are all of the electrons in an atom except for the filled shell.
*Note: This excludes full d and f shells.

Don't you wish you were one of these shells instead
of learning about scientific shells? I digress.

Examples:
Sc = [Ar]4s23d1 = 2 Valance Electrons
Tl = [Xe]6s24f145d106p1 = 3 Valence Electrons (do not count full f and d shells)


All Noble Gases have 8 or 0 Valance Electrons. Whichever you prefer to write.


Now wasn't that quick and easy? Lovely. I don't even think that a video is needed... Jokes! Of course I have a video for you!

My favourite lady...

Energy and Orbit Levels

Today I will be telling you about the electronic structure of the atom.

Energy and Orbital Levels
All atoms have energy. Some, however, are higher than others. Atoms with a high energy state are said to be Hyperkinetic.When one or more electrons have energy levels greater than their lowest energy levels, which is also known as their Ground State,  they will jump to a higher orbital level. "n" represents the energy level.


I'll just tell you what a few words mean:
Excited State: This is when one or more electrons in an atom are in any energy level other than the lowest.
Orbital: This is the region of space that an electron occupies in an energy level.
Shell: This is the set of all orbitals having the same "n" value.
Sub-Shell: This is the set of orbitals of the same type.



There are four types of orbitals, that each contain a different amount of electrons. They are: s,p,d and f.

Here are the different amount of electrons possessed by each orbital of a given "n" value:

Level 1 (n=1): s 
Level 2 (n=2): s and p
Level 3 (n=3): s, p and d
Level 4 (n=4): s, p, s and f 

It is easy to remember how to fill the shells, if you write out this simple diagram to the left and put the diagonals in. There is a bit of a trick to it too which I will tell you about later... But first, let's try an example:

What is the electron configuration of the element Potassium in it's neutral state?
First, you have to figure out how many electrons there are in potassium. (39 - 19 = 20) Therefore, there are nineteen electrons.
Next, all you have to do is fill the orbitals until no electrons are left.

*Note: s can only carry 2 electrons. p can carry 6 electrons. d can carry 10 electrons. And, finally, f can carry 14 electrons.

Electron configuration for potassium:
1s22s22p63s23p64s1

Core notation can be used which is meant to simplify our configurations. Doesn't always work out that way, though...

Example:

What is the core notation for the element Calcium?
Calcium has 20 electrons, and if we write it's configuration, it would be 1s22s22p63s23p64s2.
To simplify it, we have to find the closest noble gas to calcium, without going over, of course. So, that would be Argon, which has 18 electrons. We then take out the first 18 electrons and replace it with [Ar]. Doing this makes the answer [Ar]4s2. This may be simple for an element like calcium, but if we were trying to do Arsenic, well, that is tricky.....

Of course, like everything in life, there are Principles and Rules that must be followed....

The Pauli Exclusion Principle

Wolfgang Pauli. This strapping, young lad to the left came up with a principle that explains how electrons are arranged in an atom. He theorized that, while protons and neutrons remain constant, electrons do not. Pauli said that a certain number of electrons can be put in each specific energy level.This has been proven true. This makes sure that all electrons do not go in the first energy level. He also thought that two electrons would not be able to take up the same  state in a closed system.

The Aufbau Principle
Pauli, with the help of Bohr, also came up with the Aufbau Principle. This principle stated that the lower energy levels should be filled before the higher ones. This is indeed the case.

The Hund's Rule

Friedrich Hund. Another fine, young speciemen that came up with yet another rule. He proposed a law that stated that every electron will pair up, but only  once the previous orbital is full. These electrons will pair up with other electrons with a similar amount of energy.

Now, onto that little trick I promised you earlier...

If you ever are having a hard time remembering the configuration, just look at your Periodic Table:

It is all laid out so beautifully for you! The electronic configuration is in it's proper rows and it has all the right numbers and everything. Makes it all easy as pie, doesn't it?

Now, where would we be without a video to finish us off? Here it is: