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Atomic structure

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Question 16
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A sample of heavy, oxygen-18 enriched water, 2H218O^{2}\text{H}_2^{18}\text{O}2H218​O, has a total mass of 2.20 g.

What is the total number of neutrons in this sample?

(The Avogadro constant, L=6.02×1023 mol−1L = 6.02 \times 10^{23}\text{ mol}^{-1}L=6.02×1023 mol−1. Assume the atomic number of hydrogen is 1 and the atomic number of oxygen is 8. Assume the isotopic masses of 2H^{2}\text{H}2H and 18O^{18}\text{O}18O are 2.0 g mol-1 and 18.0 g mol-1 respectively.)

A

6.02×10236.02 \times 10^{23}6.02×1023

B

7.22×10237.22 \times 10^{23}7.22×1023

C

7.95×10237.95 \times 10^{23}7.95×1023

D

8.43×10238.43 \times 10^{23}8.43×1023

Markscheme

Atomic structure Questions

  1. A Level
  2. /Chemistry
  3. /Atomic structure

33 exam-style questions on AQA A Level Chemistry Atomic structure, covering Fundamental particles, Mass number and isotopes, and Electron configuration. Each one has a worked solution and a mark scheme showing where the marks go.

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