What colors do different metal ions produce in flame tests?

Different metal ions produce various colours in flame tests, such as red for Lithium, yellow for Sodium, and green for Copper.

Flame tests are a common method used in chemistry to identify certain metal ions. When a metal ion is heated, it absorbs energy and its electrons get excited. As these excited electrons return to their ground state, they emit energy in the form of light. The colour of this light is characteristic of the metal ion and can be used to identify it.

Lithium ions produce a crimson or red flame. This is due to the specific energy levels of the electrons in lithium ions, which emit light in the red portion of the spectrum when they return to their ground state.

Sodium ions, on the other hand, produce a bright yellow flame. This is because the energy levels of the electrons in sodium ions correspond to the yellow portion of the light spectrum. This is why sodium street lamps have a distinctive yellow glow.

Copper ions produce a green flame. This is because the energy levels of the electrons in copper ions correspond to the green portion of the light spectrum. Copper is often used in fireworks to produce green colours.

Other metal ions also produce distinctive colours. For example, potassium ions produce a lilac or purple flame, calcium ions produce a brick red flame, and barium ions produce a green flame. These colours are all due to the specific energy levels of the electrons in these ions.

Remember, flame tests are a qualitative test and can be used to identify the presence of a specific metal ion, but they cannot be used to determine the quantity of the ion present. Also, some ions may produce similar colours, so flame tests should be used in conjunction with other tests to confirm the identity of an ion.