bonding

Question 1

Ionic bonding -

Answer 1

Ionic bonding is the electrostatic force of attraction between oppositely charged ions formed by electron transfer

Question 2

Ionic bonding is stronger and the melting points

Answer 2

higher when the ions are smaller and or have higher charges

Question 3

Positive ions are s

Answer 3

Smaller compared to their atoms because it has one less shell of electrons and the ratio of protons to electrons has increased so there is greater net force on the remaing electrons holding them more closely

Question 4

The negative ions formed from groups

Answer 4

five to seven are larger than the corresponding atoms.
The negative ion has more electrons than the corresponding atom but the same number of protons. So the pull of the nucleus is shared over more electrons and the attraction per electron is less, making the ion bigger

Question 5

Within a group the size of the ionic radii

Answer 5

increases going down the group. This is because as one goes down the group the ions have more shells of electrons

Question 6

Covalent bonding

Answer 6

Is a shared pair of electrons

Question 7

Dative covalent bonding

Answer 7

A dative covalent bond forms when the shared pair of electrons in the covalent bond comes from only one of the bonding atoms. A dative covalent bond is called co - ordinate bonding.

Question 8

Draw NH4, H30, NH3BF3- covalent

Answer 8

DRAW

Question 9

The direction of the arrow goes from the atom that is providing

Answer 9

the lone pair to the atom that is deficient

Question 10

Metallic bonding

Answer 10

Metallic bonding is the electrostatic force of attraction between the positive metal ions and the delocalised electrons

Question 11

Three factors that affect the strength of metallic boning -

Answer 11

• Number of protons, strength of nuclear attraction
• The more protons the stronger the bond
• Number of delocalised electrons per atom ( The outer shell electrons are delocalised)
• more delocalised electrons the stronger the bond
• Size of the ion
• The smaller the ion, the stronger the bond

Question 12

Ionic bonding - structure -

Answer 12

Giant ionic lattice

Question 13

covalent bonding - structure

Answer 13

Simple molecular - with intermolecular forces between molecules
Macromolecular - giant molecular structures

Question 14

Metallic bonding - structure

Answer 14

Giant metallic lattice

Question 15

Ionic - covalent - metallic
- melting and boiling points

Answer 15

Ionic - high - because of giant lattice of ions with strong electrostatic forces between oppositely charged ions
Covalent simple molecular - low because of weak intermolecular forces between molecules - van der waals
Covalent macromolecular - high - because of many strong covalent bonds in macromolecular structure. Takes a lot of energy to break the strong bonds

Metallic - high because of strong electrostatic forces between positive ions and sea of delocalised electrons

Question 16

Solubility in water -

Answer 16

Ionic - generally good
Covalent Simple molecular - generally poor
Covalent macromolecular - insoluble
metallic - insoluble

Question 17

Conductivity when solid -

Answer 17

Ionic - ions can’t move fixed in lattice - poor

covalent molecular simple - poor - no ions to conduct and electrons are fixed in place - localised

macromolecular covalent - diamond and sand - poor because electrons can’t move
graphite - good as free delocalised electrons between layers

metallic - good - delocalised electrons can move through the structure

Question 18

conductivity when molten -

Answer 18

ionic - good ions can move

covalent - poor no ions

metallic - good

Question 19

Do lone pairs repel less than bonding pairs

Answer 19

NO, Lone pairs repel more than bonding pairs and so reduce bond angles - 2.5 - per lone pair

Question 20

How to explain shapes -

Answer 20

• state number of bonding pairs and lone pairs of electrons
• state that electrons pairs repel and try to get as far apart as possible
• if there are no lone pairs state that the electron pairs repel equally
• if there are lone pairs of electrons - state that lone pairs repel more than bonding pairs
• state actual shape and bond angle