Back to the lesson plan builder
Lesson length30 min45 min60 min
Questions🔀 New questions

Print the plan for yourself; the student sheet prints on its own page after it.

Science lesson plan · 9th grade (Year 10 in England) · 60 minutes

Identify metal ions with flame tests and precipitates

Chemical reactions, acids and bases

CCSS NGSS.HS-PS1-2CCSS NGSS.SEP 3England: GCSE Chemistry: Chemical analysis (identification of ions)

Objective and success criteria

Students will: Identify metal ions with flame tests and precipitates.

  • I can answer questions on today's skill on my own, without help.
  • I can explain each step and say why it works.
  • I can check my answer and spot a mistake.

Before and after

Needs first: Identify gases with laboratory tests

Leads to: the next skill in this area.

Materials: Teacher demo or video, Indicator color chart, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).

Warm-up · 6 min

  • Quick retrieval from earlier learning (Identify gases with laboratory tests). Students answer on mini whiteboards.
  • Show answers together and note who needs support in the main task.
  1. Which gas gives this result: a glowing splint relights? (hydrogen / oxygen / carbon dioxide / chlorine) → oxygenPrompt: Each common gas has its own test.
  2. Hydrogen peroxide decomposes with a catalyst and the gas relights a glowing splint. Which gas is it? (hydrogen / oxygen / chlorine / carbon dioxide) → oxygenPrompt: Hydrogen peroxide is H₂O₂.
  3. Tests for gases: which statement is NOT true? (Carbon dioxide relights a glowing splint. / Chlorine may turn damp blue litmus red before bleaching it. / Limewater is a solution of calcium hydroxide. / Hydrogen gives a squeaky pop with a lighted splint.) → Carbon dioxide relights a glowing splint.Prompt: Which gas pops and which relights a splint?

Hook · 6 min

  • Drop an antacid tablet in water (or show a clip) and ask whether a new substance is being made.
  • Share the objective: Identify metal ions with flame tests and precipitates. Read the success criteria together.

I do: model it · 12 min

  • Work through the example out loud, saying why you do each step, not just what you do.
  • Example: A flame test gives a lilac flame. Which metal ion is present?
  • Step 1: Potassium compounds give a lilac flame.
  • Step 2: So the answer is: potassium, K⁺
  • Answer: potassium, K⁺
  • Pause after each step and ask a student to say what comes next.

We do: guided practice · 12 min

  • Do these together. Students try each step on whiteboards before you reveal it.
  • Use the hints as prompts rather than giving the answer.
  1. A flame test gives a lilac flame. Which metal ion is present? (copper, Cu²⁺ / calcium, Ca²⁺ / potassium, K⁺ / sodium, Na⁺) → potassium, K⁺Prompt: Fireworks use these colours.
  2. Sodium hydroxide solution is added to a solution and a green precipitate forms. Which metal ion is present? (copper(II), Cu²⁺ / iron(II), Fe²⁺ / iron(III), Fe³⁺ / calcium, magnesium or aluminium ions) → iron(II), Fe²⁺Prompt: Each transition metal ion gives its own coloured hydroxide.

You do: independent practice · 17 min

  • Students work on the student sheet. Circulate and check the first two answers of every student early.
  • Students who finish: write a question of their own for a partner, with the answer.

The 8 questions are on the student sheet below, with answers in the key.

Exit ticket · 7 min

  • Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
  1. Sodium hydroxide solution is added to a solution and a green precipitate forms. Which metal ion is present? (copper(II), Cu²⁺ / iron(II), Fe²⁺ / iron(III), Fe³⁺ / calcium, magnesium or aluminium ions) → iron(II), Fe²⁺Prompt: Each transition metal ion gives its own coloured hydroxide.
  2. A flame test gives a green flame. Which metal ion is present? (copper, Cu²⁺ / calcium, Ca²⁺ / potassium, K⁺ / sodium, Na⁺) → copper, Cu²⁺Prompt: Fireworks use these colours.

Watch out for

  • Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
  • Remembering facts without the reason: ask "why?" and "what is the evidence?"

Support and stretch

Support

  • Review first: Identify gases with laboratory tests.
  • Use concrete materials: teacher demo or video.
  • Give the first step of each question, or a partly worked example to finish.
  • Pair with a confident partner for the guided practice.

Stretch

  • Explain a common mistake in writing and how to fix it.
  • Write a word problem that uses today's skill, then solve a partner's.

Homework and more practice

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-9.

Free lesson plan from eurekami.com/lesson-plan-builder

eurekami

Identify metal ions with flame tests and precipitates

Name

Date

Score/ 8

  1. Question 1

    A flame test gives a orange-red flame. Which metal ion is present?

    • A. calcium, Ca²⁺
    • B. potassium, K⁺
    • C. copper, Cu²⁺
    • D. lithium, Li⁺

  2. Question 2

    Sodium hydroxide solution is added to a solution and a green precipitate forms. Which metal ion is present?

    • A. copper(II), Cu²⁺
    • B. iron(II), Fe²⁺
    • C. iron(III), Fe³⁺
    • D. calcium, magnesium or aluminium ions

  3. Question 3

    Why should the wire loop be cleaned in acid before each flame test?

    • A. to stop the wire melting
    • B. to make the flame hotter
    • C. to remove traces of the last compound that could change the colour
    • D. to add sodium

  4. Question 4

    Sodium hydroxide solution is added to a solution and a brown precipitate forms. Which metal ion is present?

    • A. copper(II), Cu²⁺
    • B. iron(II), Fe²⁺
    • C. iron(III), Fe³⁺
    • D. calcium, magnesium or aluminium ions

  5. Question 5

    A flame test gives a green flame. Which metal ion is present?

    • A. copper, Cu²⁺
    • B. sodium, Na⁺
    • C. calcium, Ca²⁺
    • D. lithium, Li⁺

  6. Question 6

    Sodium hydroxide solution is added to a solution and a white precipitate forms. Which metal ion is present?

    • A. copper(II), Cu²⁺
    • B. iron(II), Fe²⁺
    • C. iron(III), Fe³⁺
    • D. calcium, magnesium or aluminium ions

  7. Question 7

    Sodium hydroxide solution is added to a solution and a blue precipitate forms. Which metal ion is present?

    • A. copper(II), Cu²⁺
    • B. iron(II), Fe²⁺
    • C. iron(III), Fe³⁺
    • D. calcium, magnesium or aluminium ions

  8. Question 8

    Firework makers want a bright green colour. Which compounds should they add?

    • A. potassium compounds
    • B. lithium compounds
    • C. copper compounds
    • D. sodium compounds

Free from eurekami.com

for the adult only

Answer key: Identify metal ions with flame tests and precipitates

  1. 1. A. calcium, Ca²⁺

  2. 2. B. iron(II), Fe²⁺

  3. 3. C. to remove traces of the last compound that could change the colour

  4. 4. C. iron(III), Fe³⁺

  5. 5. A. copper, Cu²⁺

  6. 6. D. calcium, magnesium or aluminium ions

  7. 7. A. copper(II), Cu²⁺

  8. 8. C. copper compounds