Atomic Radius

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Lauren Tindall
Posts: 15
Joined: Sat Aug 24, 2019 12:17 am

Atomic Radius

Postby Lauren Tindall » Sun Oct 20, 2019 9:43 pm

How do you find the atomic radius of an element?

Akshay Chellappa 1H
Posts: 59
Joined: Wed Sep 11, 2019 12:15 am

Re: Atomic Radius

Postby Akshay Chellappa 1H » Sun Oct 20, 2019 9:48 pm

The atomic radius of an atom is found by measuring the distance between the nuclei of two touching atoms. I believe that the atomic radius increases from right to left and from top to bottom on the periodic table.

Christine Honda 2I
Posts: 116
Joined: Sat Sep 14, 2019 12:17 am

Re: Atomic Radius

Postby Christine Honda 2I » Sun Oct 20, 2019 9:50 pm

You can calculate it using the distance between two nuclei of touching identical atoms, but as far as trends for atomic radius,
The size of an atom will decrease as you move from left to the right of a period.
The radius of atoms increases as you go down a certain group.

Varadhan_3G
Posts: 49
Joined: Wed Sep 18, 2019 12:20 am

Re: Atomic Radius

Postby Varadhan_3G » Sun Oct 20, 2019 10:04 pm

Atomic radius refers to the distance between the nuclei of two identical atoms. I don't think atomic radius is something you can easily calculate unless already given distance (use equation r=d/2 where r is radius and d is internuclear distance); you would need to use x-ray/spectroscopic methods otherwise.

Atomic radius increases down the periodic table and decreases across the periodic table. It increases down the table because the number of occupied principle energy levels is increasing, and by extension the size of orbitals is increasing. It decreases across the periodic table because protons are being added to the nucleus of an atom, increasing the attraction between the surrounding electrons and the nucleus, condensing the atom.

Example problem:
The internuclear distance between the two hydrogen atoms in an H2 molecule is measured to be 74 pm. Therefore, the atomic radius of a hydrogen atom is 74/2, 37 pm.

Abraham De Luna
Posts: 31
Joined: Sat Sep 14, 2019 12:16 am

Re: Atomic Radius

Postby Abraham De Luna » Sun Oct 20, 2019 11:29 pm

I believe that you find the atomic radius by measuring the distance between the nuclei of two touching atoms.

Kelsey Ash 1D
Posts: 50
Joined: Wed Sep 18, 2019 12:16 am

Re: Atomic Radius

Postby Kelsey Ash 1D » Mon Oct 21, 2019 12:03 pm

Atomic radius is the is half the distance between the centers of 2 neighboring atoms. Atomic radius decreases as you go across the periodic table from left to right and increases as you go down the periodic table.

105311039
Posts: 107
Joined: Fri Aug 02, 2019 12:16 am

Re: Atomic Radius

Postby 105311039 » Mon Oct 21, 2019 1:21 pm

Its the distance between two touching atoms and their nuclei.

sarahsalama2E
Posts: 164
Joined: Fri Aug 30, 2019 12:16 am

Re: Atomic Radius

Postby sarahsalama2E » Mon Oct 21, 2019 1:55 pm

Atomic radius is 1/2 the distance between the centers of neighboring atoms, and increases as you go down a group and decreases across a period. It is important to know that that ionic radii also shows the same trends.


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