chapter 7

Question 1

what is meant by the term periodicity

Answer 1

• a repeating trend in properties of elements across each period
• electron configuration
• ionization energy
• structure
• melting points

Question 2

what is meant by the term first ionisation energy

Answer 2

• the energy required to remove one electron from each atom in one mole of gaseous atoms of an element

Question 3

what factors effect the first ionisation energy

Answer 3

• atomic radius
• nuclear charge
• inner shell shielding

Question 4

what is the group trend in ionisation energy

Answer 4

• the first ionisation energy will decrease down a group
• the atomic radius will increase
• inner shell shielding increases
• nuclear attraction decreases

Question 5

what is the periodic trend in first ionisation energy

Answer 5

• the first ionisation energy will increase across a period
• nuclear charge will increase
• the atomic radius will decrease
• nuclear attraction increases

Question 6

why does Be have a higher first ionisation energy than B

Answer 6

• the 2p subshell has a higher energy than the 2s subshell
• this means its easier to remove an electron from the 2p subshell in B than the 2s subshell in Be

Question 7

why does N have a higher first ionisation energy than O

Answer 7

• N has no spin pair electrons in the 2p subshell, which have equal repulsion as far apart as possible
• O includes a spin pair in the 2p orbital, which has less repulsion
• its easier to remove an electron from a spin pair than from a lone pair

Question 8

what happens to successive ionisation energies

Answer 8

• they will increase
• the second electron will be removed from a positive ion
• the remaining electrons will be pulled closer to the nucleus

Question 9

what is metallic bonding

Answer 9

• the strong electrostatic attraction between metal cations and a sea of delocalised electrons
• metal cations are not free to move, they are held in a fixed position

Question 10

explain the electrical conductivity of metals

Answer 10

• they have high conductivity
• they can conduct in solid and in molten states
• the delocalised electrons can move throughout which means they are mobile charge carriers

Question 11

explain the melting and boiling points in metals

Answer 11

• most metals have high melting and boiling points
• they depend on the strength of the metallic bond
• a large amount of energy is required to break the bonds which leads to a high melting and boiling points

Question 12

explain the solubility of metals

Answer 12

• metals are insoluble
• they will not dissolve

Question 13

what non metals form giant structures

Answer 13

• boron
• carbon
• silicon
• the atoms are held together by a network of strong covalent bonds to form a giant covalent lattice

Question 14

what are the properties of diamond

Answer 14

• they have very high melting and boiling points
• its insoluble
• they do not conduct electricity as they have no mobile charge carriers

Question 15

what are the properties of graphite

Answer 15

• very high melting and boiling points
• insoluble
  can conduct electricity because it has a sea of delocalised electrons which are mobile charge carriers

Question 16

what is graphene

Answer 16

• a single layer of graphite
• it has the same electrical conductivity as copper
• thinnest and strongest material ever made