module 2: 5.3 covalent bonding

Question 1

define the term covalent bonding

Answer 1

covalent bonding is the strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms

Question 2

covalent bonding occurs between atoms in:

Answer 2

• non-metallic elements, H2, O2
• compounds of non-metallic elements, for example, H2O and CO2
• polyatomic ions, for example, NH4+

Question 3

describe the attraction in a covalent bond

Answer 3

the attraction is localised, acting solely between the shared pair of electrons and the nuclei of the 2 bonded atoms.

Question 4

what does a displayed formula show

Answer 4

a displayed formula shows the relative positioning of atoms and the bonds between them as lines

Question 5

define the term lone pairs

Answer 5

paired electrons that are not chared are called lone pairs

Question 6

define the term multiple covalent bonds

Answer 6

multiple covalent bonds exist when 2 atoms share more than one pair of electrons

Question 7

define the term dative covalent bond (coordinate bond)

Answer 7

a dative covalent bond (coordinate bond) is a covalent bond in which the shared pair of electrons has been supplied by one of the bonding atoms only. In a dative covalent bond the shared electron pair was originally a lone pair of electrons on one of the bonded atoms

Question 8

what is average bond enthalpy

Answer 8

average bond enthalpy serves as a measurement of covalent bond strength. The larger the value the stronger the covalent bond