DP Chemistry (first assessment 2025)

Test builder »

Question 22M.1A.HL.TZ1.5

Date	May 2022	Marks available	[Maximum mark: 1]	Reference code	22M.1A.HL.TZ1.5
Level	HL	Paper	1A	Time zone	TZ1
Command term	Deduce	Question number	5	Adapted from	N/A

5.

[Maximum mark: 1]

22M.1A.HL.TZ1.5

Naturally occurring gallium consists of the isotopes ⁷¹Ga and ⁶⁹Ga. What is the approximate percentage abundance of ⁶⁹Ga?

M_r(Ga) = 69.72.

A. 40 %

B. 50 %

C. 60 %

D. 75 %

[1]

Markscheme

C

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.