Astatine was first made in 1940. Only tiny amounts have ever been made, so most of its properties have been predicted rather than measured.
The table shows some properties of the other halogens.
| Halogen | Colour at room temperature | State at room temperature | Melting point in °C | Boiling point in °C |
|---|---|---|---|---|
| fluorine | pale yellow | gas | −220 | −188 |
| chlorine | yellow-green | gas | −101 | −34 |
| bromine | red-brown | liquid | −7 | 59 |
| iodine | dark grey | solid | 114 | 184 |
| astatine | ? | ? | ? | ? |
Explain why fluorine, chlorine, bromine and iodine are all placed in group 7 of the periodic table.
Fluorine has atomic number 9. Give the electronic configuration of a fluorine atom.
A student says: "The boiling points increase down group 7 because the covalent bonds inside the molecules get stronger." Explain why the student is wrong.
Use the data in the table and your knowledge of group 7 to predict the properties of astatine. Justify each of your predictions.
41 exam-style questions on Edexcel GCSE Chemistry 7.2 Group 7, covering 7.2.1 Physical properties of the halogens, 7.2.2 Reactions of the halogens, 7.2.3 Relative reactivity and displacement reactions of the halogens, and 7.2.4 Halogen displacement as a redox reaction. Each one has a worked solution and a mark scheme showing where the marks go.