Starter quiz
- Which of the following particles are not found in the nucleus of an atom?
- protons and neutrons
- electrons and protons
- neutrons and electrons
- electrons only ✓
- protons only
-
- What charge does an ion have if it has gained electrons?
- positive
- neutral
- negative ✓
-
- Which part of the atom is involved in chemical bonding?
- electrons ✓
- neutrons
- protons
- the nucleus
-
- Which of the following is a general property of metals?
- poor conductors of heat
- brittle
- good conductors of electricity ✓
- dull appearance
- insulators
-
- Where are metals generally located on the periodic table?
- top right
- top left
- bottom right
- bottom right
- left and centre ✓
-
- What is an ion?
- an atom that has lost or gained protons
- a neutral atom
- an atom that has lost or gained electrons ✓
- an atom with more protons than neutrons
-
Exit quiz
- What is the purpose of a flame test?
- To test for non-metal elements.
- To identify metal ions by the colour of the flame. ✓
- To determine the conductivity of a metal.
- To measure the temperature of a flame.
-
- What flame colour does potassium produce?
- yellow
- green
- lilac ✓
- blue
-
- Why is it important to clean the wire loop before conducting a flame test?
- To prevent the flame from extinguishing.
- To avoid contamination from previous tests. ✓
- To increase the temperature of the flame.
- To remove excess metal ions.
- To test multiple ions at once.
-
- What happens to electrons in metal ions when they absorb energy from the flame?
- They lose energy and stay at the same level.
- They move to a higher energy level. ✓
- They leave the atom permanently.
- They remain in the same orbit.
-
- Why do different metal ions produce different flame colours?
- Due to different electron arrangements in each metal ion. ✓
- The flame temperature changes for each metal.
- The test uses different flames for each metal.
- Different ions release more light.
-
- What is emitted when electrons in metal ions return to their ground state after excitation?
- heat
- light ✓
- sound
-
Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- Positive ions burn with distinct colours that are visible when heated above a blue Bunsen flame.
- Unique flame emission spectra are produced for each positive metal ion.
- Instrumental methods are accurate, sensitive, and rapid for detecting and identifying elements and compounds.
- A spectrometer can split light from coloured flames into flame emission spectra.
- A spectrometer can measure more than one metal ion in a single solution and the concentration of each.
Common misconception
Flame colours are unique, even in mixtures.
Explain that strong colours, like sodium's yellow, can mask others. Use spectrometry to identify masked elements.
Keywords
Flame test - A test where a chemical put into a flame produces a characteristic colour (tests for metal ions).
Spectroscope - An instrument that separates light into its component wavelengths.
Ion - An ion is an atom or group of atoms with a positive or negative charge due to the loss or gain of electrons.
Concentration - The amount of a solute dissolved in a certain volume of solvent.
Calibration curve - A graph used to determine the concentration of a substance in a sample.
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