Hund's Rule

Q. In a CCP structure of compound XY, atom X is present at octahedral voids. The ratio of 6th C. N. and 3rd C.N. for an atom X located at body-centre is a) 1 b)1/3 c) 4 d) 1/4

Q.

Hund's Rule states that:

1. No two electrons in an atom can have the same set of four quantum numbers

2. The maximum number of electrons in the shell with principal quantum n is equal to

3. None of these

4. Pairing of electrons in the orbitals belonging to the same subshell (p, d or f) does not take place until each orbital belonging to that subshell has got one electron each i.e., it is singly occupied

Q. $\text{Statement-I:}$ No two electrons in an atom can have the same set of four quantum numbers.
$\text{Statement-II:}$ Pairing of electrons in the orbitals belonging to the same subshell does not take place until each orbital of the subshell has got one electron each. In light of the above statements, choose the correct answer

Q.

Which of the following electronic configurations denote an atom in its ground state?

1. 

2. 

3. 

4. 

Q. The Lewis dot structure of beryllium fluoride molecule is:

1. 

2. 

3. 

4. 

Q. If the electronic configuration of oxygen atom is written as
it would violate :

1. Hund's rule
2. Pauli's exclusion principle
3. Both Hund's & Pauli's principles
4. None of these

Q. The orbital angular momentum for an $s$ electron will be given by:

1. Zero
2. $\frac{h}{2\pi }$
3. $\sqrt{2}.\frac{h}{2\pi }$
4. $\frac{1}{2}.\frac{h}{2\pi }$

Q. The principles that gives the correct explanation why ground state electronic configuration of $Si$ is
and not
is:

1. Heisenberg's uncertainty principle
2. Hund's rule
3. Pauli's exclusion principle
4. Aufbau Principle

Q. The preference of three unpaired electrons in the ground state of phosphorous can be explained by:

1. Pauli's exclusion principle
2. Aufbau principle
3. Heisenberg's uncertainty principle
4. Hund's rule

Q. The principles that gives the correct explanation why ground state electronic configuration of $Si$ is
and not
is:

1. Heisenberg's uncertainty principle
2. Hund's rule
3. Pauli's exclusion principle
4. Aufbau Principle

Q.

Orbital angular momentum for a d - electron is

1. 

2. 

3. 

4. 

Q. Which of the following ions has the highest magnetic moment?

1. $F{e}^{2+}$
2. $M{n}^{2+}$
3. $C{r}^{3+}$
4. $V^{3+}$

Q. Assuming that Hund’s rule is violated, the bond order and magnetic nature of the diatomic molecule $B_2$ is:

1. 0 and diamagnetic
2. 1 and paramagnetic
3. 0 and paramagnetic
4. 1 and diamagnetic

Q. The preference of three unpaired electrons in the ground state of phosphorous can be explained by:

1. Pauli's exclusion principle
2. Aufbau principle
3. Heisenberg's uncertainty principle
4. Hund's rule

Q. ques- How many number of carban atom present in 22gm CO2

Q.

Electrons in an orbital are filled according to which rule?

1. m + l

2. n + n

3. n +l

4. L + m

Q. Assign the position of the element having outer electronic configuration,
(i) ns${}^2$np${}^4$ for n=3,

Q.

Hund's Rule states that:

1. The maximum number of electrons in the shell with principal quantum n is equal to $2n^2$

2. No two electrons in an atom can have the same set of four quantum numbers

3. Pairing of electrons in the orbitals belonging to the same subshell (p, d or f) does not take place until each orbital belonging to that subshell has got one electron each i.e., it is singly occupied

4. None of these

Q. what is aufbaus principle

Q. If the electronic distribution of oxygen atom is given as
,
then it would violate:

1. Hund's rule
2. Pauli's exclusion principle
3. Both Hund's and pauli's principles
4. None of the above

Q. why pentahalides are more covalent than trihalides in nitrogen fami

Q. What are electron deficient compounds ? Are $BC{l}_3$ and $SiC{l}_4$ electron deficient species? Explain.

Q. $\begin{array}{cc}\text{Column - 1}& \text{Column - 2}\\ Species& Characteristics\\ \left(A\right)C{o}^{3+}(Z=27)& \left(p\right)\text{Total number of fully filled orbitals is nine.}\\ \left(B\right)S{c}^{3+}(z=21)& \left(q\right)\text{The value of magnetic moment (spin only) is greater than or equal to 3.87 BM.}\\ \left(C\right)C{r}^{3+}(Z=24)& \left(r\right)\text{Number of electrons with}n+l=3\text{is eight.}\\ \left(D\right)N{i}^{2+}(Z=28)& \text{(s) Number of electrons with (m = 0) may be either 11 or 12.}\\ & \text{(t) No unpaired electron.}\end{array}$

1. [A - q, r, s] [B - p, r, t]; [C - p, q, r, s]; [D - r, s].
2. [A - q, r] [B - p, r, t]; [C - p, q, r, s]; [D - r, s].
3. [A - q, r, s] [B - p]; [C - p, q, r, s]; [D - r, s].
4. [A - q, r, s] [B - p, r, t]; [C - p, q, r, s]; [D - r, s].

Q. which of the following may have same set of quantum numbers?ans is last electron of Sc and last electron of Fe, How?

Q.

Nitrogen has the electronic configuration $1s^2,2s^{2}2p_x^{1}2p_y^{1}2p_z^1$ and not $1s^2,2s^{2}2p_x^{2}2p_y^{1}2p_z^0$ which is determined by

1. Aufbau's principle

2. Pauli's exclusion principle

3. Hund's rule

4. Uncertainty principle

Q. Which of the following violates Hund's Rule?

1. 
2. 
3. 
4. 

Q. who proposed the valence shell electron pair repulsion theory and who developed and refined the theory ?

Q. Use Lewis symbols to show electron transfer between the following atoms to form cations and anions: (a) $K$ and $S$ (b) $Ca$ and $O$ (c) $Al$ and $N$.