Quick answer: Group 1 metals have one outer electron and become more reactive down the group, reacting with water to make hydrogen and an alkaline hydroxide. This Chemistry 9-10 worksheet on periodic table groups gives 20 problems from easy to hard: storing alkali metals, lithium and water and halogens at room temperature. The worked answers are on a separate page, and the worksheet is a free printable PDF.
These problems train you to use the trends in Group 1, Group 7 and Group 0. You will balance equations, interpret displacement tests and charts, and carry out short mole calculations. They begin with recall and finish with prediction, calculation and experimental design.
Use them for GCSE, IGCSE, O Level, CBSE Class 9-10 and NGSS high school chemistry.
Level: Chemistry grades 9-10 (GCSE · IGCSE · O Level · Class 9-10) · Curriculum: GCSE C1, IGCSE 9
Problem 1 Storing alkali metals ★★★
A school lab in Kampala keeps sodium in a bottle of oil.1. State two physical properties of sodium.
2. Explain why it is stored under oil.
Problem 2 Lithium and water ★★★
Lithium is added to water containing universal indicator.1. Name the two products.
2. State the colour of the indicator at the end.
3. Describe the test for the gas.
Problem 3 Halogens at room temperature ★★★
Complete the table for chlorine, bromine and iodine at room temperature.| Halogen | Colour | State |
|---|---|---|
| Chlorine | ? | ? |
| Bromine | ? | ? |
| Iodine | ? | ? |
Problem 4 Uses of noble gases ★★★
Match each gas to a use and give the reason.1. Helium: airships
2. Neon: lighting signs
3. Argon: filament lamps
Problem 5 Melting points of alkali metals ★★★
Use the chart.1. Read the melting point of sodium.
2. Describe the trend down the group.
3. Predict whether caesium melts above or below 39 °C.
Problem 6 Word equations ★★★
Write word equations.1. Sodium + water
2. Chlorine + potassium iodide
3. Lithium + chlorine
Problem 7 Balance the equations ★★★
Balance each equation.1. Li + H₂O → LiOH + H₂
2. K + Cl₂ → KCl
3. Na + Br₂ → NaBr
4. Rb + H₂O → RbOH + H₂
Problem 8 Potassium versus sodium ★★★
Potassium is 2,8,8,1 and sodium is 2,8,1.1. State the number of outer electrons in each.
2. Explain why potassium reacts more vigorously with water.
Problem 9 Fluorine and iodine ★★★
Fluorine is the most reactive halogen and iodine the least.1. Explain this using the position of the outer shell.
2. State what happens to the colour of the halogens down the group.
Problem 10 Interpreting displacement tests ★★★
Three new halogens X₂, Y₂ and Z₂ (not real symbols) were tested with solutions of their sodium salts.| Mixture | Result |
|---|---|
| X₂ + NaY | Colour change |
| Y₂ + NaX | No change |
| Z₂ + NaY | No change |
| Y₂ + NaZ | Colour change |
2. Write the order of reactivity.
3. Predict the result for X₂ + NaZ.
Problem 11 Will it react? ★★★
State whether each mixture reacts. Write a balanced equation if it does.1. Chlorine + sodium iodide
2. Iodine + sodium chloride
3. Bromine + potassium iodide
4. Chlorine + potassium bromide
Problem 12 States of the halogens ★★★
The chart shows boiling points. The melting points are fluorine −220 °C, chlorine −101 °C, bromine −7 °C and iodine 114 °C.1. State the physical state of each halogen at 25 °C.
2. Predict the state of astatine at 25 °C.
Problem 13 Hydrogen from sodium ★★★
A teacher drops 0.69 g of sodium into excess water. The equation is 2Na + 2H₂O → 2NaOH + H₂. The relative atomic mass of sodium is 23 and one mole of gas occupies 24 dm³ at room temperature.1. Calculate the moles of sodium.
2. Calculate the moles of hydrogen.
3. Calculate the volume of hydrogen in cm³.
Problem 14 Spot the errors ★★★
Diego in Texas wrote three statements. Find and correct each mistake.1. “Group 1 metals get less reactive down the group.”
2. “Chlorine is a red-brown liquid at room temperature.”
3. “Noble gases are reactive because they have 8 outer electrons.”
Problem 15 Radon boiling point ★★★
The plot shows boiling points of the noble gases (no labels on the points: they are He, Ne, Ar, Kr, Xe from left to right).1. Read the boiling point of argon.
2. Describe the trend.
3. Estimate the boiling point of radon, the next noble gas, and justify it.
Problem 16 Making iodine ★★★
Chlorine reacts with potassium iodide: Cl₂ + 2KI → 2KCl + I₂. A student uses 3.32 g of potassium iodide (relative formula mass 166).1. Calculate the moles of potassium iodide.
2. Calculate the mass of iodine formed (relative atomic mass 127).
3. Calculate the mass of chlorine needed (relative atomic mass 35.5).
Problem 17 Half equations ★★★
Chlorine displaces bromine: Cl₂ + 2Br⁻ → 2Cl⁻ + Br₂.1. Write the half equation for chlorine.
2. Write the half equation for bromide ions.
3. State which species is oxidised and which is reduced.
Problem 18 Predict the unknowns ★★★
Astatine is below iodine in Group 7 and francium is below caesium in Group 1.1. Predict the colour and state of astatine, and whether it would displace iodine from potassium iodide.
2. Predict how francium would react with water compared with caesium.
3. Justify both predictions using the trends.
Problem 19 Helium airship ★★★
An airship in the UK holds 2000 m³ of gas. At room temperature, air has a density of 1.20 kg/m³ and helium has a density of 0.17 kg/m³.1. Calculate the mass of lift each cubic metre of helium provides.
2. Calculate the total lift for the airship.
3. Explain why helium is safer than hydrogen.
Problem 20 Design an investigation ★★★
Plan an investigation to compare the reactivity of chlorine, bromine and iodine using displacement.1. State the solutions you would need.
2. List three variables to control.
3. Describe the results that show the order.
4. Give one safety precaution.
