we know that to become stable element loose or gain electrons but in quantum mechanical model s,d,f,p orbitals element's electrons are stable .how explain me clearly?

Asked by nk.pandit02 | 29th May, 2016, 04:09: PM

Expert Answer:

Elements lose, gain, or share electrons in order to achieve the stable electron configuration of the noble gas.
In Quantum Mechanical Model of an atom,

Let us recall the Bohr model. According to Bohr's model, electrons occupy certain stable orbits or shells. Each shell has definite energy. The maximum number of electrons present in the shell is given by the formula (2n2), where n is the orbit number or shell number.

Each shell is composed of one or more subshells, which are themselves composed of atomic orbitals. For example, the first (K) shell has one subshell, called 1s; the second (L) shell has two subshells, called 2s and 2p; the third shell has 3s, 3p, and 3d; the fourth shell has 4s, 4p, 4d and 4f; the fifth shell has 5s, 5p, 5d, and 5f and can theoretically hold more but the 5f subshell, although occupied in actinides, is not filled in any element occurring naturally.

Number of electrons in each shell

Each subshell is constrained to hold 4ℓ + 2 electrons at most, namely:

  • Each s subshell holds at most 2 electrons
  • Each p subshell holds at most 6 electrons
  • Each d subshell holds at most 10 electrons
  • Each f subshell holds at most 14 electrons

Therefore, the K shell, which contains only an s subshell, can hold up to 2 electrons; the L shell, which contains an s and a p, can hold up to 2 + 6 = 8 electrons, and so forth; that's why nth shell can hold up to 2n2 electrons.

Shell
name

Subshell
name

Subshell
max
electrons

Shell
max
electrons

K

1s

2

2

L

2s

2

2 + 6 = 8

2p

6

M

3s

2

2 + 6 + 10
= 18

3p

6

3d

10

N

4s

2

2 + 6 +
+ 10 + 14
= 32

4p

6

4d

10

4f

14

 

 

 

 

 

 

 

 

 

The Quantum Mechanical Model allows us to see how the 18 electrons are distributed in each sublevel within the 3rd principal energy level. Thus, in quantum mechanical model s, p, d, f orbitals are stable .

Answered by Hanisha Vyas | 30th May, 2016, 12:47: PM