The value of four quantum number for the last e^(-) of atom of element x are n = 7, l = 1, m = + 1 and s = +1//2(or) -1//2 and value of spin magnetic momentum for element 'X' is zero. Element X has two isotopes (I)_(z)X^(A) (II)._(z)X^(B) Given B-A=18 andB-2Z = 18 where A and B are atomic masses and Z is atomic number. The correct statment regarding element ''X'' is :

The value of four quantum number for the last e^(-) of atom of element

1.	The value of four quantum number for the last e^(-) of atom of element x are n = 7, l = 1, m = + 1 and s = +1//2(or) -1//2 and value of spin magnetic momentum for element 'X' is zero. Element X has two isotopes (I)_(z)X^(A) (II)._(z)X^(B) Given B-A=18 andB-2Z = 18 where A and B are atomic masses and Z is atomic number. The correct statment regarding element ''X'' is :
Answer» Element belong to `18^(TH)` group X is inner transition element X is transition element X is representative element Solution :GIVEN for element X n = 7, l = 1, m = + 1 and s = + 1/2 or - 1/2 and `mu=0` (spin only magnetic moment) 7P sub-shell, given `mu=0` then number of unpaired electrons is zero hence it will be `7p^(6)` X belong to 18 group and `7^(th)` period hence Z = 118 X is p-block element