Bonding + Periodicity

Question 1

Electronegativity

Answer 1

power of an atom to attract the pair of atoms in a covalent bond

Question 2

First ionisation energy

Answer 2

energy required to remove 1 mole of e- from 1 mole of gaseous atom to form 1 mole of gaseous 1+ ions

Question 3

Successive ionisation energies

Answer 3

• get larger as proton to electron ratio increases
• large jumps signify e- is removed from shell close to the nucleus (less shielding)

Question 4

First electron affinity

Answer 4

energy changed when 1 mole of e- is added to 1 mole of gaseous atom to form 1 mole of gaseous 1- ions

Question 5

Dative covalent bond

Answer 5

• both e- given by one atom in the covalent bond
• given by group 5, 6, 7, 8

Question 6

Covalent bond

Answer 6

• pair of e- is shared between atoms
• forms simple covalent structures
• the stronger the orbital overlap, the stronger the bond

Question 7

Metallic bond

Answer 7

• strong electrostatic forces of attraction between +ve metal ions and delocalised e-
• giant crystal structure
• strength increases with smaller atom size and greater charge

Question 8

Metallic properties

Answer 8

• malleable as sea of e- prevent repulsion
• ductile as sea of e- prevent repulsion
• high mp due to strong electrostatic forces
• conductive (e-)

Question 9

Covalent properties

Answer 9

• low mp due to weak intermolecular forces
• non-conductive (no e-)

Question 10

Ionic bond

Answer 10

• strong forces of electrostatic attraction between oppositely charged ions
• giant ionic crystal lattice

Question 11

Ionic properties

Answer 11

• brittle as layers repel
• high mp due to strong electrostatic forces
• ## conductive when molten/aqueous

Question 12

Van der Waals

Answer 12

• weakest
• RUTID!!!

Question 13

Hydrogen bonding

Answer 13

• strongest
• occurs only between H and O, N, F

Question 14

Permanent Dipole-Dipole forces

Answer 14

• middle strength

Question 15

Macromolecule properties

Answer 15

• lots of covalent bond so high mp
• non-conductive (except GRAPHITE)

Question 16

Diamond

Answer 16

• macromolecule
• each C has 4 other C

Question 17

Graphite

Answer 17

• macromolecule
• each C has 3 other C
• arranged in layers held together by VdW

Question 18

Silica

Answer 18

• macromolecule
• each S joined to 4 O

Question 19

Periodicity

Question 20

S block

Answer 20

group 1

Question 21

P block

Answer 21

transition metals

Question 22

D block

Answer 22

non-metals

Question 23

F block

Answer 23

special ones at bottom i.e. einsteinium

Question 24

Trend in atomic radius ACROSS period

Answer 24

• decreases
• shielding is constant, p number increases, nuclear attraction increases

Question 25

Trend in first ionisation energy ACROSS period

Answer 25

- increases - shielding is constant, p number increases, nuclear attraction increases

Question 26

Group 3 first ionisation energy exception

Answer 26

- e- is in p-orbital - which is of higher energy, so less energy required to remove - ionisation energy decreases

Question 27

Group 6 first ionisation energy exception

Answer 27

- 2 e- in same p-orbital - repulsion makes easier to remove e- - ionisation energy decreases

Question 28

Trend in electrical conductivity ACROSS periods

Answer 28

- decreases - metallic bonding (lots of e-), covalent bonding (no e-), monoatomic (inert)

Question 29

Trend in electronegativity ACROSS period

Answer 29

- increases - nuclear attraction increases, so greater attraction for e- in covalent bond