Atomic Structure Test |
|
1) The first ionisation energies of the elements Lithium to Neon
are given below.
Li Be B C N O F Ne
519 900 799 1090 1400 1310 1680 2080
a) Define the term first ionisation of an element, and give an equation illustrating your answer with oxygen. (2)
b) Explain why the ionisation energies show an overall tendency to increase across the period. (2)
c) Explain the irregularities in this trend for
i) Boron
ii) Oxygen (4)
d) Explain the trend in the ionisation energies with increasing atomic number in Group 1 of the periodic table. (2)
e) An element X has the following successive ionisation energies as follows:
786: 1580: 3230: 4360: 16000: 20000: 23600: 29100 KJ/mol
i) To which group in the periodic table does element X belong?
ii) Write down the outer electronic configuration of an atom of X.
iii) Suggest formulae for TWO chlorides of X. (5)
Part B
1.
An element Z has three peaks in its mass spectrum.
a.
Explain why an element
could show more than one peak in its mass spectrum.
(2)
b. Use the following information to calculate the relative atomic mass of element Z. (2)
|
Mass of Peak |
%
Abundance |
|
71 |
34 |
|
72 |
55 |
|
73 |
11 |
c.
Chlorine has two isotopes of mass 37 and 35, these have a
relative abundance of 25% and 75% respectively. Assuming that the main peaks in
mass spectrum of chlorine are due to ionised chlorine molecules (Cl2+)
i.
State and briefly explain how many peaks will be observed
(2)
ii.
Calculate the atomic mass of chlorine.
(2)
iii.
Bromine has two isotopes of mass 79 and 81. The two isotopes both have approximate relative abundances of
50%. Sketch the mass spectrum of
bromine.
(2)
d.
i.
Name the parts A to E
in the following diagram of a mass spectrometer:
(3)
ii.
State the functions of the accelerating electrode and the magnetic field.
(2)