Question

The number of electrons in an ion Y2+ is 10. The atomic number of element Y is most likely to be (a) 8
(b) 12
(c) 10
(d) 14

Answer 1

Answer:

b) 12

Explanation:

Answer 2

Answer is Option (b)

Explanation:

The ion $Y^2^+$ shows the number of valence electrons as +2.

• Which means that its a donor element.

For example -

• Magnesium has an atomic number of 12,

• As per electronic configuration - 2, 8, 2

• Its outermost shell has 2 electrons that mean Magnesium has a valency of + 2 and it can gain the stable state of neon.

Hence , off the 4 given options, Y can have an Atomic number of 12, as suggested by the two valence electrons.