The table gives information about the first four elements in Group 1 of the Periodic Table.
| Element | Atomic number | Electronic configuration | Melting point (°C\degree\text{C}°C) | Reaction with water |
|---|---|---|---|---|
| lithium | 3 | 2.1 | 180 | fizzes, floats and moves slowly on the surface |
| sodium | 11 | 2.8.1 | 98 | melts into a ball, fizzes rapidly and moves quickly |
| potassium | 19 | 2.8.8.1 | 63 | burns with a lilac flame, reacts very vigorously |
| rubidium | 37 | 2.8.18.8.1 | 39 | reacts explosively |
Francium (Fr\text{Fr}Fr) has an atomic number of 87 and is the seventh element in Group 1.
It is possible to make predictions about francium by comparison with the other elements in Group 1.
How many electrons does an atom of francium have in its outer shell?
What physical state at 15°C15\degree\text{C}15°C and approximate melting point (higher or lower than 28°C28\degree\text{C}28°C) would you expect for francium?
Predict the formula of the compound formed between francium and chlorine. Suggest a name for this compound.
Suggest how the reactivity of francium with water compares to that of rubidium. Explain your answer.
Hydrogen gas can be prepared in the laboratory by reacting zinc metal with dilute hydrochloric acid.
Balance the equation for the reaction:
…Zn(s)+…HCl(aq)→…ZnCl2(aq)+…H2(g) \dots\text{Zn}(\text{s}) + \dots\text{HCl}(\text{aq}) \rightarrow \dots\text{ZnCl}_2(\text{aq}) + \dots\text{H}_2(\text{g}) …Zn(s)+…HCl(aq)→…ZnCl2(aq)+…H2(g)State what you would observe when a lighted splint is held to the mouth of a test tube containing hydrogen gas.
Lithium can be extracted from mineral brines containing lithium ions, Li+\text{Li}^+Li+.
The stages in the extraction of lithium from brine are:
Suggest a substance (other than sodium carbonate) that could be added to brine in Stage 1 to provide carbonate ions.
Why is an excess of hydrochloric acid added in Stage 2?
Write a chemical equation for the reaction in Stage 2.
Write a chemical equation for the reaction in Stage 4.
State the colour change observed when bromine water is added to an aqueous solution of sodium iodide.
