Orbital Diagrams

Q.

What is shielding and deshielding in NMR? Give an example?

Q.

Which of the following transitions in hydrogen atoms emit photons of the highest frequency?

1. n=1 to n=2

2. n=2 to n=1

3. n=2 to n=6

4. n=6 to n=2

Q.

Which Orbital has the highest energy and why

Q. The difference between radii of 3rd and 4th orbits of $L{i}^{2+}\text{is}\Delta R_1$. The difference between the radii of 3rd and 4th orbits of $H{e}^{+}\text{is}\Delta R_2$. Ratio $\Delta R_1:\Delta R_2$ is

1. 3 : 2
2. 8 : 3
3. 2 : 3
4. 3 : 8

Q.

Explain Hunds rule and spectroscopic term of the ground state of an atom?

Q.

The number of species below that has two lone pairs of electrons in their central atom is ______. (Round off to the Nearest Integer.)

${\mathrm{SF}}_4,{{\mathrm{BF}}_4}^{-},{\mathrm{CIF}}_3,{\mathrm{AsF}}_3,{\mathrm{PCl}}_5,{\mathrm{BrF}}_5,{\mathrm{XeF}}_4,{\mathrm{SF}}_6$

Q. Write 4 quantum numbers for 2s, 2p, 3d, 4f electrons ?

Q. The number of unpaired electrons in phosphorous atom (Z=15) is:

1. 1
2. 6
3. 5
4. 3

Q.

An orbit and an orbital is the same thing.

1. True

2. False

Q. In the ground state of atomic $Fe(Z=26),$ the spin-only magnetic moment is $x\times {10}^{-1}BM$ .
(Round off to the Nearest Integer).

Q. Value of spin only magnetic moment for one of the following configuration is 2.84 bm.

Q. If $0.53\stackrel{\circ }{A}$ is the Bohr's radius for the $1^{st}$ orbit of hydrogen atom, the correct statement (s) among the following is/are :

1. The product of ${\Psi }^2$ and $4\pi r^2$ increases till it reaches at the distance of $0.53\stackrel{\circ }{A}$
2. ${\Psi }^2$ goes on increasing till it reaches at the distance of $0.53\stackrel{\circ }{A}$
3. $\Psi$ goes on increasing till it reaches at the distance of $0.53\stackrel{\circ }{A}$
4. The nodal point for the 1s orbital is at $0.53\stackrel{\circ }{A}$

Q. A d-block element has total spin value of -3 or +3 , then the magnetic moment of the element is :?

Q.

Among the following, the orbital that has the lowest energy is

1. $5\mathrm{f}$

2. $4\mathrm{f}$

3. $6\mathrm{s}$

4. $6\mathrm{p}$

Q. Which of the following statements is/are correct?

1. The radial probability distribution curves for $2s$ atomic orbital has one trough representing a radial node
2. The radial probability distribution curves for $2s$, $3p$ and $4d$ atomic orbitals are similar in shape
3. The number of angular nodes cannot be found using radial distribution curves
4. For $3s$ orbital the probability density is maximum at the nucleus.

Q.

An element has the electronic configuration $1s^2,2s^{2}2p^6,3s^{2}3p^2$. Its valency electrons are

1. 6

2. 2

3. 3

4. 4

Q. Match the List - I with List - II and select the correct set from the following sets given below:
$\begin{array}{cccc}& \text{List - I}& & \text{List - II}\\ \text{(A)}& \text{The number of subshells in an}& \text{(1)}& n^2\\ & \text{energy level}& & \\ \text{(B)}& \text{The number orbitals in a}& \text{(2)}& 3d\\ & \text{shell}& & \\ \text{(C)}& \text{The number of orbitals in a subshell}& \text{(3)}& 2l+1\\ \text{(D)}& n=3,l=2& \text{(4)}& n\end{array}$

1. $\begin{array}{ccccc}\text{Sets}& \text{(A)}& \text{(B)}& \text{(C)}& \text{(D)}\\ \text{(a)}& 4& 1& 3& 2\end{array}$
2. $\begin{array}{ccccc}\text{Sets}& \text{(A)}& \text{(B)}& \text{(C)}& \text{(D)}\\ \text{(b)}& 3& 1& 4& 2\end{array}$
3. $\begin{array}{ccccc}\text{Sets}& \text{(A)}& \text{(B)}& \text{(C)}& \text{(D)}\\ \text{(c)}& 1& 4& 3& 2\end{array}$
4. $\begin{array}{ccccc}\text{Sets}& \text{(A)}& \text{(B)}& \text{(C)}& \text{(D)}\\ \text{(d)}& 3& 4& 1& 2\end{array}$

Q.

Which one of the following elements exhibits a maximum number of valence electrons?

1. Na

2. Al

3. Si

4. P

Q. If an electron has spin quantum number of $+\frac{1}{2}$ and a magnetic quantum number of -1, it can not be present in

1. s-orbital
2. p-orbital
3. d-orbital
4. f-orbital

Q.

Name an element which has a total of two shells and there are three electrons in its valence shell.

Q. The ratio of radii of first orbits of $H$, ${He}^{+}$ and ${Li}^{2+}$ is:

1. $9:4:1$
2. $6:3:2$
3. $1:4:9$
4. $1:2:3$

Q. The order of shielding effect for different orbital is $s>p>d>f$.

1. true
2. false

Q. Stable electronic configuration & unstable electronic configuration of Mg are :

1. $1s^{2}2s^2{p}^{6}3s^2$ and $1s^{2}2s^2{p}^{6}3s^1{p}^1$
2. $1s^{2}2s^2{p}^{6}3s^0{p}^2$ and $1s^{2}2s^2{p}^{6}3s^1{p}^1$
3. $1s^{2}2s^2{p}^{6}3s^{1}4s^1$ and $1s^{2}2s^2{p}^{6}3s^1{p}^1$
4. $1s^{2}2s^2{p}^{6}3s^1{p}^1$ and $1s^{2}2s^2{p}^{6}3s^1{p}^1$

Q. Which of the following sets of quantum numbers are not possible and why? 1) n=3 , l=2 , ml=0 , ms = +1/2 2) n=3 , l=1, ml=-2 , ms =-1/2 3) n=2 , l=0, ml=0, ms= +1/2

Q. For a 3s - orbital
$\Psi \left(3s\right)=\frac{1}{a\sqrt{3}}{\left(\frac{1}{a_0}\right)}^{\frac{3}{2}}(6-6\sigma +{\sigma }^2){ϵ}^{\frac{-\sigma }{2}},$
Where $\sigma =\frac{2rZ}{3a_0}$
What is the maximum radial distance of node from nucleus is

1. $\frac{(3+\sqrt{3})a_0}{Z}$
2. $\frac{a_0}{Z}$
3. $\frac{3}{2}\frac{(3+\sqrt{3})a_0}{Z}$
4. $\frac{2a_0}{Z}$

Q. The valence electronic configuration of an element is $\left[Ne\right]3s^1$. The element is :

1. sodium
2. argon
3. fluorine
4. magnesium

Q. How many electrons can be held in a single orbital?

1. $1$
2. $2$
3. $18$
4. $8$

Q. The atomic number of element with electronic configuration: ${1s}^2{2s}^2{2p}^3$ is:

Q. An atomic orbital has two angular nodes and one radial node. It is a:

1. $3p$ orbital
2. $2p$ orbital
3. $3d$ orbital
4. $4d$ orbital

Q. The bond dissociation energy of $B-F$ in $B{F}_3$ is 646 $kJ$ $mo{l}^{-1}$ whereas that of $C-F$ in $C{F}_4$ is 515 $kJmo{l}^{-1}$. The correct reason for higher $B-F$ bond dissociation energy as compared to that of $C-F$ is:

1. smaller size of B atom as compared to that of C atom
2. stronger $0$ bond between $B$ and $F$ in $B{F}_3$ as compared to that between $C$ and $F$ in $C{F}_4$
3. significant $p\pi -p\pi$ interaction between $B$ and $F$ in $B{F}_3$ whereas there is no possibility of such interaction between $C$ and $F$ in $C{F}_4$
4. lower degree of $p\pi -p\pi$ interaction between $B$ and $F$ in $B{F}_3$ than that between $C$ and $F$ in $C{F}_4$