2006-12-15 00:47:20 · 6 answers · asked by curlash 1 in Science & Mathematics ➔ Chemistry
Atomic radii increase as you go further down the periodic table and further to the left.
Therefore, Francium is the largest as far as atomic radius. This is for two reasons:
1) It has started filling a 7s subshell, which is the highest s subshell for any element discovered so far.
2) The electrons in Francium are feeling the pull of 87 protons towards the nucleus, whereas the electrons of an element further along in the same row feel the pull of more protons towards the nucleus, making the radius just that much smaller.
2006-12-15 01:42:41 · answer #1 · answered by ruadhdarragh 3 · 0⤊ 0⤋
Francium - its valence electrons are in the 7th level, placing them further away from the nucleus than elements in rows (periods )1-6.
In its period (7th row of the chart) it will be the largest because it has the least number of protons. All of the atoms in the 7th row have their valence electrons in level 7. As the number of protons increases these 7th level electrons feel the "pull" of the nucleus more and more strongly and the electrons are "pulled" closer to the nucleus making the atoms slightly smaller as you move from left to right in the same row.
2006-12-15 22:23:34 · answer #2 · answered by The Old Professor 5 · 0⤊ 0⤋
basically you must keep in mind that the atomic radius
a)increases when u go down each group and
b)decreases when going from left to right of periodic table
why?
a) we would expect an increase in radius when going down each group becoz the outermost elcetrons in higher energy levels are farther from the nulceus
b) going across a period, there is an increase in the number of valence electrons with corresponding increase of protons, which causes a stronger attraction for the outermost electrons so valence electrons are pulled closer to the nucleus which makes the atoms smaller
hope u benefit
2006-12-15 09:54:11 · answer #3 · answered by Pharmalolli 5 · 0⤊ 0⤋
What you need to consider is the mass of the nucleus, the number of "shielding orbitals" and the number of electrons in the outer orbital.
With this information and a bit of time and effort you can work it out and understand it forever :)
good luck.
2006-12-15 08:53:07 · answer #4 · answered by Bohdisatva 3 · 0⤊ 0⤋
i think its the elements of the last period because atomid radius increases down the group.
2006-12-15 09:09:14 · answer #5 · answered by tarena 2 · 0⤊ 0⤋
I'll take a stab at Francium. because it is in the 7th period in the first group. Lots of orbitals
2006-12-15 09:34:35 · answer #6 · answered by Atello 2 · 0⤊ 0⤋