Lesson 4 of 5 · Lab Skills
Testing for Ions
🥽
🎯 Your mission
Set it up. Test it. Be amazed.
⚡ The twist
Nature loves to surprise the careful watcher.
What you'll learn
Flame tests identify metal ions by colour: lithium red, sodium yellow, potassium lilac, calcium orange-red, copper green. Sodium hydroxide gives coloured precipitates for transition metals, and silver nitrate distinguishes the halides by precipitate colour.
Key words
flame test
Identifying a metal ion from the colour it gives a flame.
precipitate test
Identifying an ion from the colour of the insoluble solid it forms.
Make a hypothesis first
Before you start: write down what you think will happen, and why.
Say your guess out loud — then find out if you were right.
Get ready
🧰 What you need
- nichrome wire
- concentrated hydrochloric acid for cleaning
- metal salt samples
- Bunsen burner
- sodium hydroxide solution
- silver nitrate solution
Get ready
⚠️ Safety first
- Clean the wire in acid between tests — an uncleaned wire gives a false sodium yellow every time.
- Concentrated acid is corrosive and silver nitrate stains and irritates: goggles and gloves throughout, teacher supervision required.
Step 1 of 4 · Read
Think about what you just learned: say what "flame test" and "precipitate test" mean in your own words before you start.
Step 2 of 4 · Do
Carry out flame tests on five known metal salts using a clean nichrome wire, then on an unknown. Follow with sodium hydroxide and silver nitrate tests and identify the unknown from your combined evidence.
Step 3 of 4 · Observe
Record what actually happened, including anything that did not match what you expected.
Step 4 of 4 · Record
Write a conclusion that answers the question this lesson opened with, and state your uncertainty.
Question 1 of 2
Question 2 of 2
Mind = blown
🔬 The more you look, the more nature shows you.
Nice work!
You got 0 of 2 right.
Next Smart Experiment
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✨ More to explore
🌍 Where you see this in real life: This shows up in your everyday life more than you'd think.
🏆 Stretch challenge (try it this week): Try one experiment in real life this week — even a tiny one.
👨👩👧 For the dinner table: “What's the most surprising thing you learned today?”
Share this experiment
Send it to a parent who's looking for a 10-minute kitchen science win.
Ready?
Testing for Ions
Set it up. Test it. Be amazed.
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Print the whole Lab Skills track
All 10th Grade Lab Skills lessons as a printable PDF, with worksheets and answer keys.