Covalent Bondig Flashcards
What is the definition of a covalent bond
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
Where are the electrons drawn in a dot and cross diagram
The electrons are drawn within the overlapping area
What is bond enthalpy related to
The length of a bond
Why is there attraction and repulsion between the nuclei
-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
What is bond length
Distance between the two nuclei is the distance where the attractive and repulsive forces balance each other
What happens if there is a higher electron density between the nuclei
There is a stronger attraction between atoms
Therefore higher bond enthalpy and shorter bond length
What is a dative covalent bond
Where one atom donates both electrons to a bond
What are the exception to the octet rules when there are more than an octet of electron
-Occurs in compounds containing heavier p-block elements, such as sulphur and phosphorous.
-These elements can hold 18 electrons in outer shell
What is the exception in the octet rule fewer than an octet of electrons
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.
When do dative bonds usually form
Occurs especially with lighter elements beryllium and boron.
