Electronic configurations and the periodic table
2 marks · NormalState the group and period of silicon (atomic number 14) and explain your reasoning.
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Silicon is in group 4, period 3. Its electron configuration is 2,8,4: 4 electrons in outer shell (group 4), 3 shells (period 3).
Also accept: Group IV, period 3
Common mistakes: Wrong group from total electrons
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Marking points
M1 · 1 mark · Correctly identifies group (4) and period (3)
B1 · 1 mark · Gives correct reason: based on configuration 2,8,4
Worked solution
Silicon: 2,8,4. Group 4 (4 outer electrons), period 3 (3 shells).
Reason: Group from outer electrons, period from number of shells.