Definitions

Question 1

Define First electron affinity:

Answer 1

the enthalpy change that takes place when one electron is added to each atom in one mole of gaseous atoms to form one mole of gaseous 1- ions

Question 2

Define Relative Isotopic mass

Answer 2

Average mass of an atom of an isotope relative to 1/12th of the mass of an atom of carbon-12.

Question 3

Define relative Atomic mass

Answer 3

Average mass of an atom of an element, relative to 1/12th of the mass of an atom of carbon-12.

Question 4

Define the First ionisation energy

Answer 4

The energy required to remove 1 mole of electrons from each atom in 1 moles of gaseous atoms to from 1 mole of gaseous 1+ ions

Question 5

Define 2nd ionisation energy

Answer 5

The energy required to remove 1 mole of electrons from each ion in 1 moles of gaseous 1+ ions to form 1 moles of gaseous 2+ ions

Question 6

Define Ionic bonding

Answer 6

Strong electrostatic attraction between two oppositely charged ions. .

Question 7

Define covalent bonding

Answer 7

The strong electrostatic attraction between two nuclei and the shared pair of electrons between them

Question 8

Define Dative bonding

Answer 8

Occurs when one atom donates both electrons in a bond

Question 9

What is a sigma bond ?

Answer 9

A bond that results from a direct overlap of two orbitals.

Question 10

What is a Pi bond?

Answer 10

A bond that is formed when two orbitals overlap sideways

Question 11

Define Electronegativity and examples of the most electronegative elements

Answer 11

The ability of atom to attract the bonding electrons in a covalent bond
- N, O , F most electronegative with a high nuclear charge

Question 12

Define a dipole

Answer 12

Difference in charge between the two atoms of a covalent bond caused by a shift in electron
density in the bond due to the electronegativity difference between elements participating in
bonding

Question 13

Define Metallic bonding

Answer 13

Strong electrostatic attraction between metal ions and the sea of delocalised electrons that surround them.

Question 14

Describe and explain London forces

Answer 14

Weak intermolecular forces between a partially charged covalent molecule, causing a constant shift in electron clouds and asymmetrical electron distribution and becomes and instantaneous dipole .
The strength of London forces depend on the size , shape and number of electrons the atoms have.

Question 15

Describe and explain permanent -permanent dipole interactions

Answer 15

Dipole-dipole attractions between polar or ionic molecules. Stronger than London forces

Question 16

Describe and explain hydrogen bonds

Answer 16

A type of intermolecular force between a hydrogen
bonded to a more electronegative atom than hydrogen like nitrogen, oxygen or fluorine.
Is the strongest intermolecular force

Question 17

define the term orbital

Answer 17

a region around the nucleus where there is a high probability of finding an electron