Information -1 : Principlal quantun number 'n' is defined as 1, 2, 3….
Information -2 : Azimaathal quantum number 'l' is defined as 0 to `(n + 1)` in integral steps of 1
Information -3 : Magnetic quantum number 'm' is defined as `- l //2` to `+ l//2`
Information -4 : Spin quantum number 's' has five possible values `-2, -10, +1, +2`
Information -5 : The sub-shell corresponding to `l = 1, 2, 3, 4, 5`..... designated as P, Q, R, S, T, U.... respectively.
Information -6 : The values of m for a given value of l give the number of orbitals in a sub-shell
Information -7 : The principles for filling electron in teh shells remains unchanged.
On the basic of above informations, answer the following questions.
The second period would begin with -

Options

A. Phosphorus
B. Sulphur
C. Chlorine
D. Titanium

Answer

B

Explanation

`n = 1, 2, 3`………
`{:(n = 1,n = 2,n = 3,),(l = 0"," 1"," 2,l = 0","1","2","3,l = 0","1","2","3","4,):}`
Possible subshells -
`{:(,1P,1Q,1R,2P,2Q,2R,2S,3P,3Q........,),(n + l =,1,2,3,2,3,4,5,3,4........,):}`
Inceasing order of energy
Each orbital has 5 electrons.
`{:(,1P,1Q,2P,1R,2Q,3P,2R........),("Total electrons",5,10,5,15,10,5,):}`
`{:("Type of subshell",1P,1Q,2P,1R,2Q,),("Number of electrons accomodate by the given subshell",10,15,10,20,15,):}`
Sol.(i) `II^(nd)` period will be start from atomic number 16 (Sulphur)
Sol. (ii) Last electron from `Z = 50` to `Z = 65` will enter in 2R subshell
Sol. (iii) For T subshell `l = 4`. Number of possible values of `m = 5`, Total electron `= 25`