DP Chemistry (last assessment 2024)

Test builder »

Question 17N.3.sl.TZ0.4c

Select a Test
Date November 2017 Marks available [Maximum mark: 3] Reference code 17N.3.sl.TZ0.4c
Level sl Paper 3 Time zone TZ0
Command term Explain Question number c Adapted from N/A
c.
[Maximum mark: 3]
17N.3.sl.TZ0.4c

It is wise to fill dental cavities before irreversible tooth decay sets in. An amalgam (alloy of mercury, silver, and other metals) is often used although many prefer a white composite material.

(c)

Explain how Inductively Coupled Plasma (ICP) Spectroscopy could be used to determine the concentration of mercury in a sample of dental filling.

[3]

Markscheme

Any three of:

sample injected into argon «plasma»

atoms «of sample» are excited/ionised

OR

electrons are promoted

electrons drop back/recombine with ions AND emit photons of characteristic energies/wavelengths/frequencies

total number of photons is proportional to concentration of element

actual concentration found from calibration/standard curve

Accept "graph/plot" for “curve”.

[Max 3 Marks]

Syllabus sections