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Posted: Tue Oct 15, 2019 10:50 pm
This could be such a basic question but how do you find atomic radius? To be honest, I looked at the solutions manual (specifically for 1F.1 where it asks to list the elements in order of decreasing atomic radius) and still don't understand how the measurement is obtained. Anything helps, thanks!

Posted: Tue Oct 15, 2019 10:53 pm
In general, the periodic table has the following trends for atomic radius:
As you move down a column, atomic radius increases.
As you move from left to right along a row, the atomic radius decreases.

Posted: Tue Oct 15, 2019 10:55 pm
Tai Metzger 3K wrote:In general, the periodic table has the following trends for atomic radius:
As you move down a column, atomic radius increases.
As you move from left to right along a row, the atomic radius decreases.

Wait, actually that sounds very familiar and I think I knew that subconsciously. Hahah thanks! But by any chance, do you know how to obtain the specific number?

Posted: Wed Oct 16, 2019 4:09 pm
The atomic radius is half the distance between the nuclei of two identical atoms bonded together. For the purpose of this class I don't think we would be calculating the exact value of the radius.

Posted: Thu Oct 17, 2019 1:12 am
We won't need to calculate the value of atomic radius. If needed, the values should be given to us.

Posted: Thu Oct 17, 2019 3:56 pm
The value of atomic radius will always be given to us.

Posted: Thu Oct 17, 2019 4:32 pm
Atomic radius is usually given in a data booklet or just in the front page of the test.

Posted: Tue Oct 22, 2019 12:48 pm
Cynthia Gong 1L wrote:The atomic radius is half the distance between the nuclei of two identical atoms bonded together. For the purpose of this class I don't think we would be calculating the exact value of the radius.

During the lecture, a picture was shown that said 2r from both nuclei of atoms bonded together. Do you know what that meant? It confused me because he said it's half the distance but then it said 2r.

Posted: Tue Oct 22, 2019 1:10 pm
I think we will always be given the atomic radius and I think the 2r was to help us understand how the atomic radii was calculated.

Posted: Tue Oct 22, 2019 1:30 pm
The atomic radius is usually determined experimentally by halving the distance between the nuclei of two atoms. There isn't a formula that I know of that can allow us to solve for the atomic radius of a given element/ion.

Posted: Wed Oct 23, 2019 11:21 am
A visual of the atomic radius trend in the periodic table:

Posted: Wed Oct 23, 2019 11:22 am
Tai Metzger 3K wrote:In general, the periodic table has the following trends for atomic radius:
As you move down a column, atomic radius increases.
As you move from left to right along a row, the atomic radius decreases.

Do we need to know the exact number though?

Posted: Wed Oct 23, 2019 11:31 am
No I don't think you need to know exactly how much the atomic radius changes, I would just know and understand the trends as you go down a group and across a period

Posted: Wed Oct 23, 2019 3:11 pm
I don't think we need to calculate atomic radius directly, but it's defined as half the distance between the centers of two neighboring atoms

Posted: Thu Oct 24, 2019 3:13 pm
We probably do not need to calculate the atomic radius, but understand the periodic trend explained in the posts above!

Posted: Thu Oct 24, 2019 3:19 pm
You won't ever be asked to calculate the actual value of atomic radii. Just know the trends.

Posted: Fri Oct 25, 2019 1:36 am
How do you differentiate between Atomic and Ionic Radius because I know they both increase when going down a group and decrease from left to right, so how are they different?

Posted: Fri Oct 25, 2019 10:05 am
In terms of looking at trends on the periodic table of atomic radii, the atomic radius can be defined as half the distance between to bonded atoms. This is because since electrons don't have a specific location, you cannot calculate exactly the distance between the center of the atom and the end of it.