Bonding

Question 1

How does the size of a positive ion compare to the size of its atom

Answer 1

Positive ion is smaller than its atom

Question 2

How does the size of a negative ion compare to the size of its atom

Answer 2

Negative ion is bigger than its atom

Question 3

What makes ionic bonding smaller

Answer 3

When the ions are small with high charges

Question 4

How do you draw a coordinate bond

Answer 4

With an arrow going from the donating species to the accepting species

Question 5

What are 3 factors that affect the strength of metallic bonding

Answer 5

• size of the ion
• number of delocalised electrons per atom
• number of protons in nucleus of atom

Question 6

How does the size of the ion affect strength of metallic bonding

Answer 6

The smaller the ion, the stronger the bond

Question 7

How does number of delocalised electrons per atom affect strength of metallic bonding

Answer 7

The more delocalised electrons, the stronger the bond

Question 8

How does number of protons in the atom affect strength of metallic bonding

Answer 8

The more protons, the stronger the bond

Question 9

What is the solubility of an ionic compound

Answer 9

Generally good

Question 10

What is the solubility of macromolecular structures

Answer 10

Insoluble

Question 11

What is the solubility of simple molecular molecules

Answer 11

Generally poor

Question 12

What is the solubility of metallic substances

Answer 12

Insoluble

Question 13

Why are metallic substances conductive

Answer 13

Delocalised electrons are free to move and carry charge

Question 14

Give a general description of ionic substances

Answer 14

Crystalline solids

Question 15

Give a general description of simple molecular substances

Answer 15

Mostly gases and liquids

Question 16

Give a general description of macromolecular substances

Answer 16

Solids

Question 17

Give a general description of metallic substances

Answer 17

• shiny metal
• malleable as positive ion in lattice are identical, so they can slide over each other
• attractive forces in lattice are the same

Question 18

What is the shape and bond angle of a molecule with 3 bonding pairs and 1 lone pair

Answer 18

Trigonal pyramidal , 107

Question 19

What is the shape and bond angle of a molecule with 4 bonding pairs and no lone pairs

Answer 19

Tetrahedral , 109.5

Question 20

What is the shape and bond angle of a molecule with 2 bonding pairs and 2 lone pairs

Answer 20

Bent , 104.5

Question 21

What is the shape and bond angle of a molecule with 5 bonding pairs and no lone pairs

Answer 21

Trigonal bipyramidal , 90 and 120

Question 22

How do you explain the shape of a molecule

Answer 22

1) state how many bonding pairs and lone pairs
2) state that bonding pairs repel to try and get as far apart as possible
3) if there are non lone pairs, say that the bonding pairs repel equally
4) if there are lone pairs, say that they repel more than bonding pairs
5) state the shape and bond angle

Question 23

What effect do lone pairs have on bond angles

Answer 23

They reduce bond angles by about 2.5 degrees per lone pair.

Question 24

Explain the trend in electronegativity across a period

Answer 24

Electronegativity increases across period as there are more protons for the same shielding, so electrons are pulled in more

Question 25

Explain the trend in electronegativity down a group

Answer 25

Electronegativity decreases down a group as atomic radius and shielding increases, so electrons not held as strongly

Question 26

When will elements in a compound for a purely covalent bond

Answer 26

When they have similar electronegativity

Question 27

When will elements in a compound form an ionic bond

Answer 27

When there is a large electronegativity difference

Question 28

Why would a polar covalent bond arise

Answer 28

When there is an unequal distribution of electrons which produces a charger separation

Question 29

How do van der walls forces arise

Answer 29

Random movement of electrons produces instantaneous dipoles, which induce dipoles in neighbouring molecules

Question 30

When do permant dipoles occur

Answer 30

Between polar molecules

Question 31

Which macromolecular structure can conduct electricity

Answer 31

Graphite