MCQ
Electron enters the sub-shell for which $(n + l)$ value is minimum. This is enunciated as
  • A
    Hund’s rule
  • Aufbau principle
  • C
    Heisenberg uncertainty principle
  • D
    Pauli’s exclusion principle

Answer

Correct option: B.
Aufbau principle
b
(b) According to the Aufbau principle electron filling minimum to higher energy level.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

In which of the following reactions, an increase in the volume of the container will favour the formation of products?
Common alum is
The atomic number of an element which shows the oxidation state of $+ 3$  is
Thermal decomposition of gaseous $\mathrm{X}_2$ to gaseous $\mathrm{X}$ at $298 \mathrm{~K}$ takes place according to the following equation :

$\mathrm{X}_2(g) \rightleftharpoons 2 \mathrm{X}(g)$

The standard reaction Gibbs energy, $\Delta_r G^{\circ}$, of this reaction is positive. At the stiur of the reaction, there is one mole of $X_2$ and no $X$. As the reaction proceeds, the number of roles of $X$ formed is given by $\beta$. Thus, $\beta_{\text {equitibrium }}$ is the number of moles of $\mathrm{X}$ formed at equilibrium. The reaction is carried out at a constant total pressure of 2 bar. Consider the gases to behave ideally. (Given : $R=0.083 \mathrm{~L} \mathrm{bar}^{-1} \mathrm{~mol}^{-1}$ )

($1$) The equilibrium constant $K_P$ for this reaction at $298 \mathrm{~K}$, in terms of $\beta_{\text {equilibs, um }}$, is

($A$) $\frac{8 \beta_{\text {equilibrium }}^2}{2-\beta_{\text {equilibrium }}}$    ($B$) $\frac{8 \beta_{\text {equititrium }}^2}{4-\beta_{\text {equilibrium }}^2}$     ($C$) $\frac{4 \beta_{\text {equilibrium }}^2}{2-\beta_{\text {equilibrium }}}$   ($D$) $\frac{4 \ell_{\text {equitibrium }}^2}{4-\beta_{\text {equilibrium }}^2}$

($2$) The $INCORRECT$ statement among the following, for this reaction, is

($A$) Decrease in the total pressure will result in formation of more moles of gaseous $\mathrm{X}$

($B$) At the start of the reaction, dissociation of gaseous $\mathrm{X}_2$ takes place spontaneously

($C$) $\beta_{\text {equilibrium }}=0.7$

($D$) $\quad K_c<1$

Given the answer question ($1$) and ($2$) 

Solubility product $(K_{sp})$ of the salts $MX\,,\, MX_2\,,\, M_3X$ at temperature $'T'$ are $4 \times 10^{-8}\,,\, 3.2 \times 10^{-14}$ and $2.7 \times 10^{-15}$ respectively. Solubilities of the salt at temperature $'T'$ are in the order
Each orbital has a nodal plane. Which of the following statements about nodal planes are not true :
The $IUPAC$  name of the compoundis

$C{H_3} - \mathop {\mathop {CH - }\limits_{|\,\,\,\,\,\,\,} }\limits_{C{H_3}\,} C{H_2} - C{H_2} - Cl$

Given $N _2(g)+3 H _2(g) \rightarrow NH _3(g) ; \Delta_r H ^{\circ}=-92.4 kJ mol ^{-1}$. What is the standard enthalpy of formation of $NH _3$ gas?
How many protons are present in $1.8\,g \,NH_4^+$ ............. $N_A$
Which one of the following elements has the highest ionisation energy