4.2 Covalent Bonding (4.2.0 - 4.2.3)

Question 1

Covalent Bonding Definition

Answer 1

A covalent bond is the electrostatic attraction between positively charged nuclei and shared pairs of bonding electrons.

Question 2

How many bonding electrons are in a single covalent bond?

Answer 2

A single covalent bond consists of two shared bonding electrons, a double covalent bond consists of four shared bonding electrons and a triple covalent bond consists of six shared bonding electrons.

Question 3

Bond length definition

Answer 3

Bond length is the distance between the nuclei of the bonded atoms.

Question 4

How does a coordinate covalent bond differ from a ‘regular covalent bond’?

Answer 4

A coordinate covalent bond differs from a ‘regular’ covalent bond because both the bonding electrons come from one atom.

Question 5

Dimer definition

Answer 5

A dimer is a larger molecule composed of two identical smaller molecules and can be linked by coordinate covalent bonds or by hydrogen bonds.

Question 6

What kind of atoms can form a coordinate covalent bond?

Answer 6

Atoms in molecules that are electron-deficient (lacking in electrons) are able to form coordinate covalent bonds. An example of such a molecule is aluminium chloride. Despite being a metal and non-metal atom bonded together, the bonding in aluminium chloride is actually polar covalent, not ionic.

Question 7

Difference in electronegativity ≥ 1.8 units is what kind of bond?

Answer 7

Ionic

Question 8

Difference in electronegativity 0.5 − 1.7 units is what kind of bond?

Answer 8

Polar covalent

Question 9

Difference in electronegativity 0.1 − 0.4 units is what kind of bond?

Answer 9

Non-polar (weakly polar) covalent

Question 10

Difference in electronegativity 0 units is what kind of bond?

Answer 10

Pure covalent

Question 11

Bond Dipole definition

Answer 11

A bond dipole is caused by the unequal sharing of electrons in a covalent bond.

Question 12

Bonds between atoms with small differences in electronegativity have _ ionic character and _ covalent character.

Answer 12

Bonds between atoms with small differences in electronegativity have less ionic character and more covalent character.

Question 13

The _ the electronegativity difference between the atoms, the _ the polarity of the bond and the _ its ionic character

Answer 13

The greater the electronegativity difference between the atoms, the greater the polarity of the bond and the greater its ionic character