Art and Business Studies

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PRACTICE EXAMINATION QUESTIONS FOR 1.1 ATOMIC STRUCTURE
(includes some questions from 1.4 Periodicity)
1.(a)Complete the following table.
|Relative mass|Relative charge|
Neutron|||
Electron|||
(2)
(b)An atom has twice as many protons as, and four more neutrons than, an atom of 9Be. Deduce the symbol, including the mass number, of this atom. ..................................................................................................................................... (2)

(Total 4 marks)
2.(a)Define the terms
(i)mass number of an atom,
........................................................................................…............................... (ii)relative molecular mass.
........................................................................................…............................... ........................................................................................…............................... (3)

(b)(i)Complete the electron arrangement for a copper atom. 1s2 ……………………………......................................................................... (ii)Identify the block in the Periodic Table to which copper belongs. ........................................................................................…............................... (iii)Deduce the number of neutrons in one atom of 65Cu

........................................................................................…............................... (3)

(c)A sample of copper contains the two isotopes 63Cu and 65Cu only. It has a relative atomic mass, Ar, less than 64. The mass spectrum of this sample shows major peaks with m/z values of 63 and 65, respectively. (i)Explain why the Ar of this sample is less than 64.

........................................................................................…............................... (ii)Explain how Cu atoms are converted into Cu+ ions in a mass spectrometer. ........................................................................................…............................... ........................................................................................…............................... (iii)In addition to the major peaks at m/z = 63 and 65, much smaller peaks at m/z = 31.5 and 32.5 are also present in the mass spectrum. Identify the ion responsible for the peak at m/z = 31.5 in the mass spectrum. Explain why your chosen ion has this m/z value and suggest one reason why this peak is very small.

Identity of the ion .............................................................................................
Explanation for m/z value ................................................................................ ........................................................................................…...............................

Reason why this peak is very small .................................................................. ........................................................................................…............................... (6)

(Total 12 marks)
3.A sample of iron from a meteorite was found to contain the isotopes 54Fe, 56Fe and 57Fe. (a)The relative abundances of these isotopes can be determined using a mass spectrometer. In the mass spectrometer, the sample is first vaporised and then ionised. (i)State what is meant by the term isotopes.

........................................................................................................................... ........................................................................................................................... (ii)Explain how, in a mass spectrometer, ions are detected and how their abundance is measured. How ions are detected........................................................................................
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