Covalent Bondig

Question 1

What is the definition of a covalent bond

Answer 1

A covalent bond is the strong electrostatic attraction between two positive nuclei and the shared pair of electrons
The sharing is electrons allow for a noble gas configuration

Question 2

Where are the electrons drawn in a dot and cross diagram

Answer 2

The electrons are drawn within the overlapping area

Question 3

What is bond enthalpy related to

Answer 3

The length of a bond

Question 4

Why is there attraction and repulsion between the nuclei

Answer 4

-positive nuclei are attracted to the area of electrons density between the two nuclei
- repulsion occurs because the two positively charged nuclei repel each other as well as the electron

Question 5

What is bond length

Answer 5

Distance between the two nuclei is the distance where the attractive and repulsive forces balance each other

Question 6

What happens if there is a higher electron density between the nuclei

Answer 6

There is a stronger attraction between atoms
Therefore higher bond enthalpy and shorter bond length

Question 7

What is a dative covalent bond

Answer 7

Where one atom donates both electrons to a bond

Question 8

What are the exception to the octet rules when there are more than an octet of electron

Answer 8

-Occurs in compounds containing heavier p-block elements, such as sulphur and phosphorous.
-These elements can hold 18 electrons in outer shell

Question 9

What is the exception in the octet rule fewer than an octet of electrons

Answer 9

Occurs in compounds containing lighter p-block elements, especially boron and beryllium.
Should lose 2 (Be) or 3 (B) electrons but atoms are small and outer electrons tightly held.
-Ionisation energies are high.
Electrons shared and formation of covalent compounds.

Question 10

When do dative bonds usually form

Answer 10

Occurs especially with lighter elements beryllium and boron.