Gases in the atmosphere

Worked examples (6)

• 1State the proportions of gases in air (Getting started)
• 2Name the most abundant gas (Getting started)
• 3Read a gas from a pie chart (Building confidence)
• 4Volume of nitrogen in a sample of air (Building confidence)
• 5Identify a gas and explain the percentages (Stretch)
• 6Calculate two gas volumes and check the total (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Calculate the percentage of oxygen (Getting started)
• 2Name the apparatus and the colour change (Getting started)
• 3Explain two procedure steps (Building confidence)
• 4Explain why you cool before reading (Building confidence)
• 5Explain a low result (Stretch)
• 6Calculate % oxygen from the rusting-iron method (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Classify oxides as acidic or basic (Getting started)
• 2Identify hydrogen and its product (Getting started)
• 3Write the equation for burning magnesium (Building confidence)
• 4Burning sulfur and naming the acid (Building confidence)
• 5Predict products and equations across the elements (Stretch)
• 6Work back from observations to the element (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended

Worked examples (6)

• 1Define thermal decomposition (Getting started)
• 2Test for carbon dioxide (Getting started)
• 3Write the decomposition equation (Building confidence)
• 4Explain the observations for copper(II) carbonate (Building confidence)
• 5Calculate the mass of CO₂ released (Stretch)
• 6Use loss in mass to find the oxide (Stretch)

Model answers (6)

• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style
• ✓Model answer — 4WSD0/1C style — extended
• ✓Model answer — 4WSD0/1C style — extended