Question

Need HElp please :/

I am doing a project about analyzing different trends on the periodic table using some data of the first 20 elements. I already graphed their data and answered all of the questions that I'm required to answer, but I'm stuck with this question because I'm not sure how to do it. Can someone help me? Thanks.



Here is the question:

Using graphical method or any other, estimate the atomic radius and predict a first ionization energy for Cesium.

Answer 1

how the radius change in a group?

Answer 2

The atomic radius increases as you go down the group

(but i need the \(\sf numerical\) size of Cs)

Answer 3

I know, but you know the numerical radius of Li, Na and K?

Answer 4

yes,
Li =155 pm
Na = 190 pm
K=235 pm

Answer 5

you can get the rate of increase from Li to Na and from Na to K?

Answer 6

ej: 190pm/155pm

Answer 7

okay....
i'll try..

for Li to Na, i got approx. 0.82 while Na to K, i got approx. 0.81
so should I use 0.8? to calculate for Cs??

Answer 8

you have two periods, 2x 0.8

Answer 9

Rb then Cs, so it will be...lol how to do it?
should I do this:
235 (K) x 1.6 = 376 pm??

Answer 10

aah so 235/1.6=147 pm?

but why is it that Cs is smaller than K? it should be larger right?

Answer 11

yes you are right, sorry for the mistake

Answer 12

thanks

Answer 13

how about the ionization energy?
the rates are different.
Li=0.52 Mj/mol

Na=0.50 Mj/mol

K=0.42 Mj/mol

Answer 14

yes we should find a correlation with the increase of the atomic number, anyway is going to be smaller than 0.42. Let me think if i found some strategy

Answer 15

you will have more electrons, more shielding from the nucleus