Question

What is the next atomic orbital in the series ${\mathbf{1s}},{\mathbf{2s}},{\mathbf{2p}},{\mathbf{3s}},{\mathbf{3p}}$?

Answer 1

All you have to remember for atomic orbitals is the Aufbau principle and its rules.
In this we can see about the Aufbau principle and the atomic orbital.
BASIC STEPS:
From the principal quantum number is to calculate the number of orbitals, use ${n^2}$. There are ${n^2}$ orbitals for each energy level. For $n = 1$, there is ${1^2}$ or one orbital. For$n = 2$, there are ${2^2}$ or four orbitals.
With the lowest energy first the subsequent electron and electron entering the orbital are fed in the order of increasing energies.
It determines the number of the electrons present in an atom.

Complete answer:
The $4s$ shell fills before the $3d$ shell, as it has a lower energy level than the $3d$ shell,
In order as: $1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p.....1s$ will be filled as first, with the highest no. of $2$ electrons. $2s$will be filled next, with the maximum of $2$ electrons. $2p$ will be filled next, with a maximum of $6$electrons.
The number of electrons present in the given series is the d subshell can hold a maximum of $10$ electrons. The order of filling the first two subshells of the third shell —for example, the electron configuration of aluminum, with$13$ electrons, is $1{s^2},2{s^2},2{p^6},3{s^2},3{p^1}$
At the lowest energy level, the one closest to the atomic center, there is a single 1s orbital that can hold $2$ electrons. At the next energy level, there are four orbitals; a $2s,2{p^1},2{p^{{2^{}}}}$ and a $2{p^3}$. Each of these orbitals can hold $2$ electrons, so a total of $8$ electrons can be found at this level of energy
From the principal quantum number is to calculate the number of orbitals, use ${n^2}$. There are ${n^2}$orbitals for each energy level. For $n = 1$, there is${1^2}$or one orbital. For $n = 2$, there are ${2^2}$or four orbitals.
The next orbital to be filled in the above-given series is $4s$.
Electron orbital:
The order of the electron orbital starting from least to greatest, order of the electron orbital energy levels is$1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p,6s,4f,5d,6p,7s,5f,6d,7p$ . Since electrons all have the same charge, they stay as away as possible because of the repulsion. ... For example, the $2p$ shell has three p orbitals

Note:
The $4s$ shell fills before the$3d$ shell, as it has a lower energy level than the$3d$shell.
As orbitals correspond to the number of the subshell. $1$ corresponds to s orbital. $2$corresponds to $2s,2p$. 3 corresponds to $3s,3p,3d$. 4 corresponds to $4s,4p,4d,4f$ .Thus$1s,2s,2p,3s,3p,3d$ the next is $4s....$It determines the number of the electron that the atom has. In order as: $1s,2s,2p,3s,3p,4s,3d,4p,5s,4d,5p.....1s$ will be filled as first, with the highest no. of $2$electrons.$2s$ will be filled to next, with the maximum of $2$electrons. $2p$will be filled next, with the highest no of 6 electrons.