Question

What shell would be the first to have a g – subshell? How many orbitals will be possible in a g – subshell?

Answer 1

We have to know that the electron shells are surrounding from the outer part of the atomic nucleus. And it is a group of atomic shells and the value of the principal quantum number, ‘n’ is equal to the same. An electron shell contains one or more sublevels or electron subshells. All the electron shells are separated by electron orbitals and these subdivisions are known as subshells.

Complete answer:
There are a total four subshells present which are, s, p, d and f subshells in an electronic configuration. For each subshell, the value of quantum numbers are different. For, s – subshells, the principal quantum number (n), orbital angular momentum quantum number (l) are one and zero respectively.
For, p – subshell; n starts from two and l is equal to one.
For, d – subshell; n starts from three and l is equal to two.
For, f – subshell; n starts from four and l is equal to three.
Therefore, the g – shell means it is at a higher level. Which means, the principal quantum number (n) is equal to five. Hence, the shell would be the first to have a g – subshell is ${5^{th}}$shell. And orbital angular momentum quantum number (l) is equal to $n - 1$
Thus, $n = 5$
$l = n - 1$
Now we can substitute the known values and on simplification we get,
$= 5 - 1 = 4$
For $l = 4,m = - l\,to\, + l$
Therefore, $m = - 4, - 3, - 2, - 1,0, + 1, + 2, + 3, + 4$
Hence, the number of orbitals possible in a g – subshell is equal to $9$.

Note:
As we know that there are a total of four quantum numbers present. That is, principal quantum number (n), orbital angular momentum quantum number (l), magnetic quantum number $\left( {{m_l}} \right)$and the electron spin quantum number$\left( {{m_s}} \right)$. These quantum numbers are used to describe the energy and position of the electron present in an atom.