The element magnesium has three stable isotopes: magnesium-24, magnesium-25, and magnesium-26.
Complete the table to show the number of protons and neutrons in each isotope of magnesium.
| Isotope | Mass number | Number of protons | Number of neutrons |
|---|---|---|---|
| magnesium-24 | 24 | 12 | 12 |
| magnesium-25 | 25 | ||
| magnesium-26 | 26 |
Explain, in terms of electrons, why the three isotopes of magnesium have identical chemical properties.
State what is meant by the term relative atomic mass, ArA_{\text{r}}Ar.
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.
41 exam-style questions on Edexcel IGCSE Chemistry Atomic structure. Each one has a worked solution and a mark scheme showing where the marks go.