Other examples of ionic bonding
2 marks · EasyAn oxygen atom (atomic number 8) forms an oxide ion. How many electrons has the oxide ion? Show your working.
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
10 electrons (±0)
Common mistakes: States 8; States 6
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Shows working: 8 + 2 = 10
A1 · 1 mark · Correct final answer: 10 electrons
Worked solution
Oxygen atom has 8 electrons. An oxide ion (O2–) has gained 2 electrons: 8 + 2 = 10 electrons.