Answer:
In Ca F₂
Ca²⁺ has 18 electrons with
K Shell 2 electrons
L shell 8 electrons
M shell 8 electrons
N shell 2 electrons.
and
F⁻ has 10 electrons with
K shell 2 electrons
L shell 8 electrons
In K₂S
Each K⁺ has 18 electrons with electronic arrangement
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
and S²⁻has 18 electrons with electronic arrangement
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
with 18 electrons.
Explanation:
CaF₂ is an ionic compound formed by a calcium ion and 2 flouride ions.
Atomic no. of Ca is 20.It has 20 protons in nucleus and 20 electrons.
Electronic arrangement:
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
N shell 2 electrons.
It loses 2 electrons of the valence N shell to get the nearest noble gas configuration of Ar. SInce it loses 2 electrons it has two protons more than electrons and forms Ca⁺² ion.
F has atomic no. 9 .It has 9 protons in nucleus and 9 electrons.
Electronic arrangement:
K shell 2 electrons
L shell 7 electrons
It must gain 1 electron to get the nearest noble gas configuration(completely filled valence shell) of Ne.
2 F atoms take up one electron each that is lost by Ca to get an extra negative charge F⁻ and attain the noble gas configuration .Each Flourine atom now has 1 electron more than proton and becomes F⁻ ion.
So in Ca F₂
Ca²⁺ has 18 electrons with
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
N shell 2 electrons.
and
F⁻ has 10 electrons with
K shell 2 electrons
L shell 8 electrons
K₂S is an ionic compound formed by 2 potassium ions and one sulfide ion.
Atomic no. of K is 19.It has 19 protons in nucleus and 19 electrons.
Electronic arrangement:
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
N shell 1 electron
It loses 1 electron of the valence N shell to get the nearest noble gas configuration of Ar.It loses 2 electrons of the valence N shell to get the nearest noble gas configuration of Ar. SInce it loses one electron it has one proton more than electron and forms K⁺ ion.In K₂S two such K⁺ ions are formed.
S has atomic no. 16 .It has 16 protons in nucleus and 16 electrons.
Electronic arrangement:
K shell 2 electrons
L shell 8 electrons
M shell 6 electrons
S atom take up 2 electrons that is lost by the two K atoms to get two extra negative charge S²⁻ and attain the noble gas configuration . Sulfur atom now has 2 electrons more than protons and becomes S²⁻ ion.
So in K₂S
Each K⁺ has 18 electrons with electronic arrangement
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
and S²⁻has 18 electrons with electronic arrangement
K shell 2 electrons
L shell 8 electrons
M shell 8 electrons
with 18 electrons.
