A pretty weird Table

Here are the answers to my last blog, 5th August 2012

The Periodic Table contains all the known chemical elements on Earth. Each element has a chemical symbol, consisting of one or two letters. For example, ‘H‘ is hydrogen, ‘He‘ is helium, etc..

It’s easy to look them up since everyone, everywhere uses the same symbols. It’s an international code.

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The Periodic Table in the form first devised by Dimitri Mendeleev

The shape or design of the table may seem pretty weird, but there are good reasons for it.

In the table the noble gases occur as a group of elements on the far right hand side. A group is a vertical column of elements:

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The chemical non reactiveness and stability of the noble gases is attributed to their full outer shell of electrons.

So what is a full outer shell of electrons? Or, in other words, how many electrons do the noble gases have in their outer shell, since theirs is described as being full?

And why is it called The Periodic Table anyway? The design of the table appears to be pretty weird, so is there something special about grouping elements in vertical columns (called groups) like this?

Fluoride not flouride

As if you could take flour on a ride.

Here’s the answer to my last blog, 4th August 2012

A bonding diagram for the formation of lithium fluoride

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lithium and fluorine atoms
electron arrangements shown below atoms

Lithium fluoride contains lithium ions, Li+ and fluoride ions, F- bonded ionically.

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lithium fluoride, LiF

When atoms react they gain the electron arrangement of the nearest noble gas in The Periodic Table and hence become more stable.

The lithium ion has an electron arrangement the same as the noble gas helium and the fluoride ion has the same electron arrangement as neon.

So what is The Periodic Table and what are the electron arrangements of the noble gases?

A rose by any other name..

Here’s the answer to my last blog, 1st August 2012

Lithium and fluorine react to make lithium fluoride.

When naming ionic compounds:

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NaCl = sodium chloride
NaClO = sodium chlorate (I)
The (I) in roman numerals is the oxidation number of the chlorine

Can you draw a bonding diagram for the formation of lithium fluoride from lithium and fluorine atoms?

sodium + chlorine –>

The answers to my last blog, 29th July 2012

The electron arrangement of the sodium ion, Na+ [2,8] is the same as that of the Noble gas neon.

Similarly, the electron arrangement of the chloride ion, Cl- [2,8,8] is like that of argon.

The Noble gases are a group of elements with particularly stable electron arrangements. When the elements sodium and chlorine react forming sodium chloride a lot of energy is given out in a violent exothermic reaction. The product, sodium chloride, is a lot more stable than the reactants, sodium and chlorine. This reaction is shown in the composite photo below:

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Sodium metal reacts violently with chlorine gas to make sodium choride

So what is the product formed when lithium reacts with fluorine?