Home > Community > Why does Pb have a higher electronegativity than Sn?
Upvote

28

Downvote
+ Electronegativity
+ Chemistry
Posted by
Kurt Guntheroth

Why does Pb have a higher electronegativity than Sn?

David Goodman  Follow

Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

Lead has an electronic configuration of [Xe] 4f¹⁴ 5d¹⁰ 6s² 6p² Inorder to achieve half filled electronic configuration which stabilises the lead atom, it attracts on the shared pair of electrons with greater force making it more electronegative than Tin.

More

Upvote

VOTE

Downvote
John Engelman  Follow
But Sn is also one electron away from half filled 5p. How would you explain that?More
Upvote

VOTE

Downvote
Antonello Frau  Follow

The explanation is actually well-known.

  • Elements in Period 6 get f orbitals for the first time. 4f subshell has relatively poor shielding effects, thus it's harder for the atoms to lose the outer electrons, increasing electronegativity. (similar reasons also account for some chemical properties of Period 4 elements, like $\ce{H2SeO4}$'s oxidizability)

  • Relativistic effects also contribute. For a very informal (and actually incorrect) understanding, just imagine that the electrons in these heavy atoms move fast and their masses increase and their energy decreases.

More

Upvote

VOTE

Downvote