1. Extend
Calculate the relative atomic mass of the following mixtures of isotopes.
90.5% 20Ne and 9.5% 22Ne
7.6% 6Li and 92.4% 7Li
5.9% 54Fe, 91.8% 56Fe and 2.3% 57Fe
92.2% 28Si, 4.7% 29Si and 3.1% 30Si
The table shows the natural relative abundance of the main isotopes of mercury, Hg.
Calculate the relative atomic mass of mercury. Give your answer to 1 decimal place.
Explain why the relative atomic mass of mercury is shown as 201 in the periodic table.
Mass number
198
199
200
201
202
204
% Relative abundance
10.0
16.9
23.1
13.2
29.9
6.9

2. 6 mark practice – Write the question down
* An atom of beryllium has an atomic number of 4 and a mass number of 9.
Describe the numbers and arrangements of the protons, neutrons and electrons in this atom.
(6)
Success Criteria
Say how many protons, neutrons and electrons Beryllium has in full sentences.
Say where the protons and neutrons are found.
Say where the electrons are found.
Describe the electron configuration – say how many electrons there are in each shell. E.g. 2 in the first shell.
Draw a labelled diagram to support your answer.
Check punctuation, spelling and grammar.
HPs awarded for effort and attainment