Atomic Emission Spectra

Question 1

What is AES (Atomic Emission Spectra) used for?

Answer 1

Analysing a sample for the presence of different metalic elements

Question 2

How does a Flame test work?

Answer 2

• Sample is heated and electron absorbs energy
• It jumps from ground state orbital to higher energy orbital
• Then it falls back from higher energy orbital to orginal ground state orbita; releasing energy
• Energy released is in the form of light
• Characteristic wavelength of light (colours) is emmitted by different metals, allowing metals to be identified

Question 3

Why can we use flame test on non-metals

Answer 3

Energy relesed by non-metals is not on the visible spectrum

Question 4

State some positives of flame tests:

Answer 4

• Accessible
• Cheap
• Easy to use

Question 5

State some negatives of flame tests:

Answer 5

• Multiple electrons jump orbitals to produce multiple light wavelengths that mix
• Highly subjective test
• Limited to small amount of metals

Question 6

How does AES work

Atomic Emission Spectroscopy

Answer 6

Same as a flame test except:
* Hotter flame used to test more metals
* Each electron’s individual emission is recorded before mixing

Question 7

How are light emissions in AES recorded?

Answer 7

Using an Emission Spectrum:
- If emitted light falls on visible spectrum, corresponding lines on emission spectrum will be coloured
- Absorbed light will be represented by black lines

Question 8

What are some positives of AES?

Answer 8

• Objective results
• More accurate and precise testing method
• Can test wider range of metals

Question 9

What are some negatives of AES?

Answer 9

• Expensive
• Harder to use
• Less accessible