Atomic Radius of Argon!

[Zishi]

Hello! Can anyone explain me that why IS the atomic radius of argon greater than any other elements of the Period 3rd despite the fact that it has a greater nuclear charge? I'm very much confused at this point. :|

 

[OakMoon!]

Can you tell me the source that says so?
Argon has the least atomic radius in the period 3 just as the electron theory says so. If you need a proof scroll down to the last section of this wikipedia page: http://en.wikipedia.org/wiki/Atomic_radius

Hope this helped

 

[Zishi]

See the answer to question to 4(a)(iii): http://www.xtremepapers.net/CIE/Int.../9701 - Chemistry/9701_s03_ms_1+2+3+4+5+6.pdf

Plus at many other sites it is also shown that Argon has the largest radius.

 

[OakMoon!]

Now thats odd. Data booklet also gives argon with a larger atomic radius. It has something to do with the bonds between atoms or molecules. With argon having only vander wall forces while other members of period 3 have either covalent or metallic bonding when they exist at there standard state. But I don't have any idea how it is related to atomic radius.

 

[beacon_of_light]

Zishi's right!

In the data booklet, see the atomic radii on page 88. Argon has the largest atomic radius even larger than sodium. So the marking scheme is correct.

 

[beacon_of_light]

And the reason is that there are weak van der waal forces b/w argon atoms, thereby , the atomic radius increases.Atoms are not squashed but hardly touch each other. See the link below to get an idea...

http://www.chemguide.co.uk/atoms/proper ... adius.html

 

[OakMoon!]

You are absolutely right Mr. --- (beacon of light)

 

[beacon_of_light]

Oh well... thanks

Always right in chemistry