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Atomic structure

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Question 15

The element magnesium has three stable isotopes: magnesium-24, magnesium-25, and magnesium-26.

a.

Complete the table to show the number of protons and neutrons in each isotope of magnesium.

IsotopeMass numberNumber of protonsNumber of neutrons
magnesium-24241212
magnesium-2525
magnesium-2626
[2]
b.

Explain, in terms of electrons, why the three isotopes of magnesium have identical chemical properties.

[1]
c.

State what is meant by the term relative atomic mass, ArA_{\text{r}}Ar​.

[2]
d.

A sample of magnesium contains 78.99% magnesium-24, 10.00% magnesium-25, and 11.01% magnesium-26.

Use this information to calculate the relative atomic mass of magnesium in this sample. Give your answer to two decimal places.

[2]

Atomic structure Questions

  1. IGCSE
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  3. /Atomic structure