Question

The electronic configurations of four particles A, B, C and D are given below:

A	2, 8, 8
B	2, 8, 2
C	2, 6
D	2, 8

Which electronic configuration represents:

1. magnesium atom?
2. oxygen atom?
3. sodium ion?
4. chloride ion?

Answer 1

1. The electronic configuration of particle B represents the magnesium atom because its atomic number is 12.
2. Electronic configuration of particle C represents oxygen atom because its atomic number is 8.
3. The electronic configuration of particle D represents the sodium ion. Atomic number of sodium is 11 and it loses one electron to stabilise and forms sodium ion containing 10 electrons.
4. The electronic configuration of particle A represents the chloride ion. The atomic number of Chlorine is 17, and it gains one electron to stabilise, forming a chloride ion with 18 electrons.