DP Chemistry (last assessment 2024)
Question 18M.3.hl.TZ2.18a
| Date | May 2018 | Marks available | [Maximum mark: 2] | Reference code | 18M.3.hl.TZ2.18a |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Draw, Identify | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
18M.3.hl.TZ2.18a
The conductivity of a germanium semiconductor can be increased by doping.
(a)
Draw the Lewis (electron dot) structure for an appropriate doping element in the box in the centre identifying the type of semiconductor formed.
[2]
Markscheme
ALTERNATIVE 1
B/Ga in circle AND Type of semiconductor: p-type
showing 3 electron pairs AND one lone electron «and hole»
ALTERNATIVE 2
P/As in circle AND Type of semiconductor: n-type
showing 4 electron pairs AND one non-bonded electron
Accept any group 13 element labelled as p-type.
Accept showing 7 electrons.
Accept any group 15 element labelled as n-type.
Accept showing 9 electrons.
Accept dots or crosses for electrons.
[2 marks]