Page 172 - An Introduction to Analytical Atomic Spectrometry - L. Ebdon

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Appendices.

Appendix A:
Revision Questions

1 What is meant by the following terms:

(a) ground state;
(b) resonance line;
(c) excited state;
(d) absorption line half-width;
(e) self-absorption;
(f) Maxwell-Boltzmann distribution;
(g) atomic fluorescence?

2 Describe the factors which cause broadening of spectral lines. In atomic absorption spectrometry,
why is it preferable for the source line-width to be narrower than the absorption profile? How can this
be achieved? What are the differing requirements for resolution in monochromators for atomic
emission and for atomic absorption spectrometry?

3 Explain the operation of:
(a) a photomultiplier tube;
(b) a pneumatic nebulizer;
(c) an electrothermal atomizer;

(d) a hollow-cathode lamp.

4 Describe the principles of:
(a) atomic emission spectrometry;
(b) atomic mass spectrometry.
Discuss the instrumental requirements for these two techniques.