DP Chemistry (first assessment 2025)

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Question 20N.1A.SL.TZ0.5

Date	November 2020	Marks available	[Maximum mark: 1]	Reference code	20N.1A.SL.TZ0.5
Level	SL	Paper	1A	Time zone	TZ0
Command term	Determine	Question number	5	Adapted from	N/A

5.

[Maximum mark: 1]

20N.1A.SL.TZ0.5

What is the relative atomic mass, $A_{r}$ , of an element with this mass spectrum?

A. $24.0$

B. $24.3$

C. $24.9$

D. $25.0$

[1]

Markscheme

B

Examiners report

Well answered question with more than 70% of candidates able to find the RAM of an element from isotope relative abundances.

Syllabus sections

Structure 1. Models of the particulate nature of matter » Structure 1.2—The nuclear atom » Structure 1.2.3—Mass spectra. Mass spectra are used to determine the relative atomic masses of elements from their isotopic composition. Interpret mass spectra in terms of identity and relative abundance of isotopes.