Question

If an electron can have three values of spin quantum numbers $(+\frac{1}{2},0\text{and}-\frac{1}{2})$, which of the following conclusion(s) would be correct?

• A. Li would be in the first period of the periodic table
• B. The total number of elements in the third period would have been 27
• C. Zinc (Zn) will belong to s-block in the new periodic table
• D. Ga will be $1^{st}$ member of d-block in new periodic table

Answer 1

Answer: (A), (C), (D)

Ga will be $1^{st}$ member of d-block in new periodic table

Three spin values would mean that each orbital would now have 3 electrons instead of two. The number of orbitals would be the same as $s=1,p=3,d=5$. The number of electrons in the sub shells would be 3, 9 and 15 respectively. The new configuration would be:
$1s^{3}2s^{3}2p^{9}3s^{3}3p^{9}4s^{3}3d^{15}4p^{9}5s^3\dots$
(a) Li would be in the first period of the periodic table as it has 3 electrons.
(b) The total number of elements in the third period would have been 12 since the $3^{rd}$ period contains s and p block elements only.
(c) Zinc will belong to s-block in the new periodic table with configuration $1s^{3}2s^{3}2p^{9}3s^{3}3p^{9}4s^3$
(d) Ga will be $1^{st}$ member of d-block in new periodic table since it comes after Zn.