Question

How many electrons in an atom with atomic number $105$ that can have $(n+1)=8$?

• A. 30
• B. 17
• C. 15
• D. Unpredictable

Answer 1

The correct option is B 17

$17$ electrons in an atom can have $(n+1)=8$

with atomic number $105$

Total number of electrons$=105$

The electron in the outermost shell$=5f^{14}6d^{3}7s^2$

In $5f$, by using formula $(n+l)=5+3=8$

Also the $14$ electrons

In $6d,n+l=6+2=8$

Also the $3$ electrons

So total of $14+3=17$ electrons