Topic 3 Flashcards
What is ionic bonding?
It’s strong electrostatic forces of attraction between the opposite charged ions and are usually in a lattice structure
What two things does the strength of the ion depend on?
The size of the radius and charge
What are the evidence for existence of ions?
1) migration of ions:
-electrolysis, the negative ion (anion) goes to the anode
The positive ion (cation) goes to the cathode)
2) electron density map
- Iona are Separated from each other due to the gap between them
What is polarisation?
It’s the distortion of electron density map of a negative ion
What is the polarisation power?
Its the ability of a positive ion to distort the density map of a neighbouring negative ion
What increases the polarisation power of a positive ion?
The size of the ion —> the smaller the radius the more polarisation power
The charge of the ion —> the larger the charger the more polarisation power it has
What properties does a negative ion have when they are highly distorted?
They have a large radius and a great charge
What is a covalent bond?
It’s the electrostatic attraction between the pair of electron and the two nuclei
What are the two types of bonding ?
- Sigma 2. Pi
Describe the sigma bonding:
Sigma bonding occurs between the s&s orbital, S&P orbital and P&P orbital when they are head to head only
Sigma bonding is very string
Describe Pi bonding :
Pi bonding occurs between the p&p orbital when they are side to side
This bonding type is very weak
What is bond length?
It’s the length between the nuclei of two atoms
What is the strength of covalent bond:
The amount of energy needed to break the one mole of the bond at gaseous state
What is electro negativity ?
The ability of an atom to attract the bonding pair of electrons in a covalent bond
What is the name and angle of a molecule with 2 bp and 0lp
Linear and has 180 degree angle
