Question

What are "Loan Pairs"?

Answer 1

Two people applying for a mortgage? The term is LONE pairs!

Explanation:

Both oxygen and the halogens (and other atoms) can have lone pairs that are not involved in bonding, but nevertheless influence the geometry around the atom that bears the lone pairs. For example, ethers can be represented as `R-O-R`. The structure around the oxygen is based on a tetrahedron, in that the lone pairs are stereochemically active.

The `R-O-R` bond angles should be `109.5""^@`; because the lone pairs around oxygen are more active than bonding pairs, they tend to compress this angle (I don't know the value offhand!, `~= 104""^@`). Remember that while the bonding pairs and the non-bonding pairs are arranged as VSEPR would predict, WE DO NOT describe the geometry based on the disposition of the lone pairs, but on the bonding pairs ONLY. Water and ethers are thus described as BENT molecules. Capisce?

Answer 2

Its lone not loan.

Explanation:

Those electrons which are present in valence shell but do not take part in the formation of covalent bond or do not share between two atoms are called Lone Pair of electron. For example oxygen atom has six valence electrons but only two of them take part in covalent bond and remaining two pairs do not take part. These two pairs are called Lone Pairs.