Bonding

Question 1

Define covalent bonding

Answer 1

Sharing of electrons between 2 non metals

Question 2

Define ionic bonding

Answer 2

The gaining or losing of electrons between metals and non metals

Question 3

Define metallic bonding

Answer 3

The electrostatic attraction between the positively charged atomic nuclei of metal atoms and a sea of delocalised electrons in the metal

Question 4

Define lone pairs

Answer 4

Exist where 2 or more atoms are bonded but both electrons originate from 1 of the atoms (not paired)

Question 5

What are the 2 types of intermolecular bonds?

Answer 5

Van der waals forces and hydrogen bonding

Question 6

Define hydrogen bonding

Answer 6

Occurs between molecules containing hydrogen bonded directly to an electronegative atom e.g. fluorine, oxygen, nitrogen

Question 7

Define polarity

Answer 7

A measure of how electrons are shared

Question 8

Define non polar

Answer 8

Electrons are shared equally

Question 9

Define polar

Answer 9

One has a greater attraction/affinity (strength of attraction. amount of pull) for the electrons than the other (unequal)

Question 10

Define electronegativity

Answer 10

The ability of an atom to attract the electron pair in a covalent bond to itself.

Question 11

Define ion

Answer 11

A charged particle

Question 12

Describe the structure of a giant ionic lattice

Answer 12

Between opposite charged ions there are strong electrostatic attraction leading to the high
boiling/melting point.
When the ions are free to move they conduct electricity
Brittle/shatter as when like charges align they repel

Question 13

Name 3 properties of covalent bonding

Answer 13

Low boiling/melting point
Weak intermolecular forces
Can’t conduct electricity

Question 14

Describe co-ordinate bonding

Answer 14

When the atom is donating electrons has a pair of electrons that isn’t being used in a bond (lone pair)

Question 15

Why are atoms held together in a covalent bond?

Answer 15

Their nuclei which has an overall positive charge are attracted to the shared electrons

Question 16

How does instantaneous dipole-induced dipole forces work?

Answer 16

The dipole on one side of the atom induces dipoles on nearby atoms
Atoms are now attracted to each other by weak forces
The greater the number of electrons, the stronger the attraction and the greater the energy needed to separate the particles.

Question 17

Define the pauling scale

Answer 17

A scale for measuring electronegativity values increase across periods values decreases down the groups.

Question 18

When does dipole dipole interaction occur?

Answer 18

Between molecules containing polar bonds acting in addition to the basic Van der Waal’s forces the extra attraction between dipoles means that more energy must be put in to separate molecules. They get higher boiling points than expected for a given mass.

Question 19

Describe hydrogen bonding

Answer 19

Gives rise to even higher boiling points
Bonds between hydrogen and the 3 most electronegative elements: fluorine, oxygen and nitrogen (extremely polar)
Because of the small sizes of hydrogen, fluorine, nitrogen and oxygen the particle charges are concentrated in a small volume thus leading to a higher charge density.
Makes the intermolecular attractions greater and leading to even higher boiling points.

Question 20

Describe metallic bonding

Answer 20

Cannot transfer electrons, unless there is a non-metal atom.
Metallic bonding is that metals consists of a lattice of positive ions existing in a “sea” of delocalised electrons.
The positive ions tend to repel one another and this is balanced by the electrostatic attraction of these positive ions for the negatively charged “sea” of delocalised electrons.
The number of delocalised electrons depends on how many electrons have been lost by each metal atom.
The metallic bonding spreads throughout so metals have giant structures.

Question 21

Define delocalised electrons

Answer 21

They aren’t tied to the particular atom

Question 22

What are properties of metals?

Answer 22

Good conductors of heat and electricity, malleable, ductile and high melting points

Question 23

What influences the strength of metals?

Answer 23

Charge of the ion, sizes of the ion (the smaller the ion, the closer the electrons are to the positive nucleus and the stronger the bond)