Explanation Question Structures

Question 1

What are the key points to include when explaining how emission spectrum is created?

Answer 1

• electrons exist in fixed energy levels
• electrons promoted
• emit energy as light at a specific frequency
• planck’s equation (E=hv)
• atoms of different elements have different energy levels
• lines come in series
• lines converge at higher frequency

Question 2

What are the key points to include when answering ionisation enthalpy questions?

Answer 2

• outer electron - distance from nucleus, how many shells
• shielding - less or more?
• attraction - between outer electron & nucleus
• energy required to remove outer electron

Question 3

What are the key principles to consider when explaining trends in g1/g2 reactivity?

Answer 3

As you go down the group:
- outer electron(s) - distance from the nucleus, how many shells
- shielding
- attraction - between outer electrons and nucleus
- energy required to remove outer electron(s)

Question 4

What are the key principles to consider when comparing thermal stability of group 2 carbonates?

Answer 4

Compare:
- charge density of group 2 ion (decreases as go down group)
- pull on carbonate ion - polarising it
- energy required to decompose carbonate ion
- time it takes to decompose carbonate ion

Question 5

What are the key principles to consider when answering melting point questions?

Answer 5

• type of bonding/structure
• which bonds are actually breaking?
• strength of bonds/attractions
• energy required to break/overcome them