Drawing diagrams of electronic configurations
3 marks · EasyAn atom of boron has an atomic number of 5.
State how many electrons a boron atom has.
Write its electronic configuration as numbers showing the electrons in each shell.
Draw a diagram to show the electronic configuration of boron, using circles for shells and dots or crosses for electrons.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) 5
(b) 2, 3
(c) — · must show two shells (circles) shown around a nucleus, 2 electrons in first shell (dots/crosses), 3 electrons in second shell (dots/crosses)
Common mistakes: wrong number of electrons; wrong number in each shell; extra shells
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States number of electrons in boron as 5.
B1 (b) · 1 mark · Gives correct electronic configuration: 2, 3.
B1 (c) · 1 mark · Draws a clear diagram: two concentric circles (shells), 2 electrons in first shell, 3 in second shell. Accept dots or crosses for electrons.
Worked solution
a) Number of electrons = atomic number = 5.
b) Electronic configuration: first shell can hold 2, second shell holds remaining 3, so 2, 3.