Calcium chloride
3 marks · EasyGive the electronic configuration of a fluoride ion (F^-).
Explain how a lithium atom changes to a lithium ion when forming lithium fluoride.
Draw a dot-and-cross diagram for the lithium ion formed.
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.
Show answer
(a) 2,8
(b) — · must show Describes lithium loses one electron; forms Li^+
(c) — · must show Li^+ in square brackets, No outer electrons, + charge
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Marking points
B1 (a) · 1 mark · States 2,8 as electronic configuration for F^-.
B1 (b) · 1 mark · Explains that lithium atom loses one electron to form Li^+ ion.
B1 (c) · 1 mark · Draws a correct dot-and-cross diagram for Li^+: square bracket, no electrons, correct charge shown.
Worked solution
a) F^- electronic configuration: 2,8 b) A lithium atom loses its one outer electron, forming a Li^+ ion. c) Li^+ dot-and-cross diagram: square brackets with no electrons and a + outside.