The halogens are elements in Group 7 of the Periodic Table.
Table 1 shows some properties of the first four halogens.
| Halogen | Appearance at room temperature | Boiling point in ∘C^\circ\text{C}∘C |
|---|---|---|
| fluorine | pale yellow gas | −188-188−188 |
| chlorine | pale green gas | −34-34−34 |
| bromine | red-brown liquid | 595959 |
| iodine | grey-black solid | 184184184 |
Tennessine (Ts) is a synthetic element located at the bottom of Group 7, below astatine.
Predict the physical state of tennessine at room temperature.
Predict how the colour of tennessine compares with the colour of iodine.
A student added bromine water to a colourless solution of potassium iodide.
Describe the colour change observed in the solution.
Explain why a reaction occurs, by comparing the reactivity of the halogens involved.
Complete the balanced chemical equation for the reaction between bromine and potassium iodide:
Br2+2KI→………⋯+………… \text{Br}_2 + 2\text{KI} \rightarrow \dots\dots\dots\dots + \dots\dots\dots\dots Br2+2KI→………⋯+…………
