lone pair

British

noun

chem a pair of valency electrons of opposite spin that are not shared between the atoms in a molecule and are responsible for the formation of coordinate bonds

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Example Sentences

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For example, an atom with four single bonds, a double bond, and a lone pair has an octahedral electron-group geometry and a square pyramidal molecular structure.

From Textbooks • Feb. 14, 2019

Group 15 elements such as nitrogen have five valence electrons in the atomic Lewis symbol: one lone pair and three unpaired electrons.

From Textbooks • Feb. 14, 2019

Phosphorus and nitrogen can form sp3 hybrids to form three bonds and hold one lone pair in PF3 and NF3, respectively.

From Textbooks • Feb. 14, 2019

It readily combines with a molecule containing an atom with a lone pair of electrons.

From Textbooks • Feb. 14, 2019

It does not matter which X is replaced with a lone pair because the molecules can be rotated to convert positions.

From Textbooks • Feb. 14, 2019

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023