Group 8/0 - Topic 6

Question 1

Why are noble gases chemically inert?

Answer 1

• They have full outer shells so 8 electrons in their outer shell (except helium, which has 2- but this shell is still full)
• Their electronic configurations demonstrate their full outer shells and this makes them unreactive with other elements because they are very stable

Question 2

Symbol for helium:

Answer 2

He

Question 3

Electronic configuration of helium:

Answer 3

2

Question 4

Uses of helium + explanation:

Answer 4

• airships - low density, less dense than air
• MRI - doesn’t dissolve in water

Question 5

Symbol for neon:

Answer 5

Ne

Question 6

Electronic configuration of neon:

Answer 6

2, 8

Question 7

Uses of neon + explanation:

Answer 7

• neon lights - gas glows when current passes through it
• luminous tubing

Question 8

Symbol for argon:

Answer 8

Ar

Question 9

Electronic configuration of argon:

Answer 9

2,8,8

Question 10

Uses of argon + explanation:

Answer 10

• light bulbs
  
  • protects filament from reacting with O2/N as it is inert so doesn’t react with wire and can get hot with combusting, stops filament burning away as it is inert and not flammable
  • argon is used in light bulb as it is inert meaning it is unreactive due to it being noble gas and have a full outer shell (stable electronic structure) - so doesn’t need to go gain/lose/transfer/share any electrons as it doesn’t need to form any bonds to gain a full outer shell
• welding - to create inert environment to prevent metal reacting with O2

Question 11

Symbol for krypton:

Answer 11

Kr

Question 12

Electronic configuration of krypton:

Answer 12

2,8,18,18,8 or 2,8,8,18

Question 13

Uses of krypton + explanation:

Answer 13

• used to generate lasers
• light bulbs
  
  • protects filament from reacting with O2/N as it is inert so doesn’t react with wire and can get hot without combusting, stops filament burning away as it is inert and not flammable, unreactive with hot metal filament
  • as it is inert meaning it is unreactive due to it being noble gas and have a full outer shell (stable electronic structure) - so doesn’t need to go gain/lose/transfer/share any electrons as it doesn’t need to form any bonds to gain a full outer shell

Question 14

Symbol for xenon:

Answer 14

Xe

Question 15

Electronic configuration of xenon:

Answer 15

2,8,18,18,8

Question 16

Uses of xenon + explanation:

Answer 16

• used to generate lasers
• light bulbs
  
  • protects filament from reacting with O2/N as it is inert so doesn’t react with wire and can get hot without combusting, stops filament burning away as it is inert and not flammable, unreactive with hot metal filament
  • as it is inert meaning it is unreactive due to it being noble gas and have a full outer shell (stable electronic structure) - so doesn’t need to go gain/lose/transfer/share any electrons as it doesn’t need to form any bonds to gain a full outer shell

Question 17

Symbol for radon:

Answer 17

Rn

Question 18

Electronic configuration of radon:

Answer 18

2,8,18,32,18,8

Question 19

Uses of radon + explanation:

Answer 19

• no good uses
• radioactive gas
• carcinogenic so causes cancer + health problems
• dangerous
• produced as a byproduct of the decomposition of uranium

Question 20

List all the noble gases:

Answer 20

• Helium (He)
• Neon (Ne)
• Argon (Ar)
• Krypton (Kr)
• Xenon (Xe)
• Radon (Rn)

Question 21

Why is argon unreactive, like helium, but has a higher boiling point than helium?

Answer 21

• unreactive due to full outer shell meaning it is very stable
• higher bp as it is larger than He so more and stronger forces between atoms

Question 22

Why were the noble gases not discovered until recently?

Answer 22

• colourless gases in relatively low abundance that don’t react with anything

Question 23

Boiling point vs atomic number for noble gases graph:

Answer 23

• due to strong stronger IMFs
• boiling points and densities of the noble gases increase with increasing relative atomic mass (going down the group) as the atom gets larger so there are more forces between atoms (stronger) which needs more energy to overcome so higher MPT

Question 24

What is the structure of noble gases and what is their appearance like?

Answer 24

• monatomic
• colourless gases at RTP

Question 25

How do the boiling points and densities of noble gases change and why?

Answer 25

• boiling points and densities of the noble gases increase with increasing relative atomic mass (going down the group 0/8) and the atom gets larger which means there are more forces between atoms (stronger) which needs more energy to overcome to stronger MPT
• forces of attraction between noble gases increase down Group 8/0 like halogens due to stronger IMFs

Question 26

How does the reactivity of the noble gases change?

Answer 26

reactivity of noble gases increases as you go down Group 8/0