Electronic Configuration of Atoms

In a given atom no two electrons can have the same values for all the four quantum numbers. This is called

An ion has $18$ electrons in the outermost shell is:

If n = 6, the correct sequence for filling of electrons will be :

Number of unpaired electrons in ${\mathrm{N}}^{2+}$ is

For which one of the following sets of four quantum numbers, an electron will have the highest energy?

Assertion : The ${19}^{\mathrm{th} }$electron in potassium atom enters into $4\mathrm{s}-$orbital and not the $3\mathrm{d}-$orbital.

Reason : $(\mathrm{n} + \mathrm{l})$ rule is followed for determining the orbital of the lowest energy state.

The ground state electronic configuration of the elements, $\mathrm{U}, \mathrm{V}, \mathrm{W}, \mathrm{X}, \mathrm{Y}$ and $\mathrm{Z}$ are as follows:
$\mathrm{U} 1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^3$
$\mathrm{V} 1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^1$
$\mathrm{W} 1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^2$
$\begin{array}{ll}\mathrm{X}& 1 {\mathrm{s}}^{2}2 {\mathrm{s}}^{2}2{\mathrm{p}}^{6}3 {\mathrm{s}}^{2}3{\mathrm{p}}^{6}3 {\mathrm{d}}^{5}4 {\mathrm{s}}^2\end{array}$
$\mathrm{Y} 1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^{6}3{\mathrm{d}}^{10}4{\mathrm{s}}^{2}4{\mathrm{p}}^6$
Determine which sequence of elements best fits the following statements
(i) element-forms a carbonate which is not decomposed by heating
(ii) element is most likely to form coloured ionic compounds
(iii) element is a mono atomic gas

In the electronic configuration of which of the given elements, 'Aufbau principle' or $\left(n+l\right)$ rule is violated?

In any atom which sub-shell will have the highest energy in the following

If the principal quantum number $\text{n}=6,$ the correct sequence of filling of electrons will be:

When $4\mathrm{f}$ level is completely filled with electrons, the next electron will enter into the sub-shell whose $(\mathrm{n}+\mathrm{l})$ is equal to:

The total number of electrons present in all the $\mathrm{p}-$orbitals in the ground state of ${}_{34}\mathrm{Se}$ are

What is the total number of unpaired electrons in one mole of ${}_{29}\mathrm{Cu}$?

The orbital diagram in which both the Pauli's exclusion principle and Hund's rule are violated is

Which is the correct order of increasing energy of the listed orbitals in the atom of titanium?

'The orbitals of equal energy (degenerate) are occupied with one electron each before the pairing of electron starts.' This is according to the:

Which rule of filling of electrons states that every orbital in a sublevel is singly occupied before any orbital is doubly occupied, all the electrons in singly occupied orbitals have the same spin?

Four electrons, each of mass $m_e$ are in a one dimensional box of size $L$. Assume that, the electrons are non-interacting, obey the Pauli exclusion principle and are described by standing De Broglie waves confined within the box. Define $\alpha =\frac{h^2}{8m_e{L}^2}$ and $U_0$ to be the ground state energy. Then,