Module 1 Covalent bonding Flashcards
What is the definition of a covalent bond?
Two non-metals sharing a pair of electrons to form structure isoelectronic to noble gases
What does the term Isoelectronic mean?
An isoelectronic compound has the same electron structure as another atom (For e.g. Covalent compounds are isoelectronic to the noble gases).
Why do Covalent bonds stay together?
As the non-metal atoms get closer to each other, they’re attracted to the positive nuclei so the electrons being shared are caught between the two nuclei. This balances the repulsion of the two positive nuclei.
What is a dative bond?
A dative bond is where one shared pair of electrons in the covalent bond both come from the same atom.
Give an example of a dative bond.
In an Ammonium ion (NH4) 3 of the hydrogen atoms contently bond giving one of their electrons to the electron pair. However one of the hydrogen becomes a +ve ion and the electron pair comes from the nitrogen atom.
How is a dative bond showed in a display formula?
An arrow pointing towards the atom that didn’t give electrons to the pair.
What does the term Electron deficient mean?
When an atom is electron deficient, it means that there is room for more pairs of electrons in its bonding level (Outer shell).
Why are covalent compounds poor conductors of electricity?
There are no ions free to move the electric charge.
why do covalent compounds have low melting points?
They have weak intermolecular forces that are easily overcome at low temperatures.
