Geology Reference
In-Depth Information
(c) Wavelengths of elemental spectra vary systemati-
cally with atomic number, providing a powerful
means of determining how much of each element
is present in a geological sample. X-ray spectra are
particularly useful for the chemical analysis of
minerals and rocks.
6.3 Determine the (minimum) values of x and y in the
following formulae, consistent with the valencies
of the elements concerned:
Na OSiO Si FMgClScO PO BN
xyxy xy xyxyxyxy
6.4 (a) Use the K α wavelength data below to plot a
graph to verify Moseley's Law for the ele-
ments Y to Ag (see Appendix B and Figure 6.6).
Estimate the values of k and σ .
Atkins, P., Overton, T., Rourke, J., et al . (2010) Inorganic
Chemistry , 5th edn. Oxford: Oxford University Press.
Barrett, J. (2002) Atomic Structure and Periodicity . Cambridge:
Royal Society of Chemistry.
Gill, R. (ed.) (1996) Modern Analytical Geochemistry . Harlow:
Longman.
Scerri, E.R. (2011) The Periodic Table - a Very Short Introduction .
Oxford: Oxford University Press.
Element
Z
Wavelength/pm
Y
39
83.0
Zr
40
78.7
Nb
41
74.8
Mo
42
71.1
ru
44
64.4
rh
45
61.5
pd
46
58.7
Exercises
ag
47
56.1
6.1 Identify the elements having the atomic numbers
listed below. Work out their electronic configura-
tions, distinguishing between core and valence
electrons. Establish the block and group to which
each element belongs, and work out the valency.
(b) The radioactive element technetium (Tc, Z = 43;
named from the Greek technetos = 'artificial' -
Figure 6.3) does not occur naturally on Earth,
but can be produced artificially. Predict
the wavelength of its K α X-ray line and
the corresponding quantum energy (in keV)
( h = 6.626 × 10 −34 J s = 4.135 × 10 −15 eV s;
c = 2.997 × 10 8 m s −1 in a vacuum.)
Z = 358914
,,,,
6.2 Work out the electronic configurations of the fol-
lowing atoms, representing the electron core by the
symbol of the preceding inert gas. To which blocks
do they belong?
Ti Ni As U           Search WWH ::

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