Number of molecules/species from the following having one unpaired electron is __________.
[2024]
(2)
| Molecules | Number of electrons | Electronic configuration | Number of unpaired electrons |
| 16 | 2 | ||
| 17 | 1 | ||
| 15 | 1 | ||
| 14 | 0 | ||
| 18 | 0 |
Number of molecules having bond order 2 from the following molecule is _________ .
[2024]
(2)
| Molecule | Electronic configuration | Bond order |
The total number of species from the following in which one unpaired electron is present, in ____________ .
[2024]
(4)
| Molecule | Electronic configuration | Number of unpaired electrons |
| 0 | ||
| 2 | ||
| 1 | ||
| 1 | ||
| 0 | ||
| 1 | ||
| 0 | ||
| 1 |
Total number of electrons present in molecular orbitals of and is _________ . [2024]
(6)
| Molecule | Electronic configuration | Electrons present in |
| 2 | ||
| 1 | ||
| 3 |
Sum = 2 + 1 + 3 = 6
When and are the wave function of atomic orbitals, then is represented by: [2024]
(4)
Constructive overlap of wavefunctions give bonding molecular orbital ( or ) and destructive overlap of wavefunctions give antibonding molecular orbitals ( or ). Axial overlap of orbitals give (or ) bond and lateral overlap of orbitals give (or ) bond.

Which of the following linear combination of atomic orbitals will lead to formation of molecular orbitals in homonuclear diatomic molecules [internuclear axis in z-direction]?
(A) and
(B) and
(C) and
(D) and
(E) and
Choose the correct answer from the options given below: [2025]
(A) and (B) only
(E) only
(D) only
(C) and (D) only
(3)

Which of the following molecules(s) show/s paramagnetic behavior? [2025]
(A)
(B)
(C)
(D)
(E)
Choose the correct answer from the options given below:
B only
A and C only
A and E only
A and D only
(4)
| Molecule | Electronic Configuration | Number of Unpaired Electrons | Magnetic Nature |
| 2 | Paramagnetic | ||
| 0 | Diamagnetic | ||
| 0 | Diamagnetic | ||
| 2 | Paramagnetic | ||
| 0 | Diamagnetic |
What is the number of unpaired electron(s) in the highest occupied molecular orbital of the following species:
? [2023]
0, 1, 2, 1
2, 1, 2, 1
0, 1, 0, 1
2, 1, 0, 1
(1)
| Species | Number of Unpaired Electrons |
| 0 | |
| 1 | |
| 2 | |
| 1 |
According to MO theory the bond orders for , CO and respectively, are [2023]
1, 3 and 3
2, 3 and 3
1, 2 and 3
1, 3 and 2
(1)
| Species | Molecular Orbital configuration | Bond order = |
The bond order and magnetic property of acetylide ion are same as that of [2023]
(2)
| Species | Total number of electrons | Bond order | Unpaired electrons (n) | Magnetic momentum |
| Acetylides ion | 14 | 3 | 0 | 0 |
| 17 | 1.5 | 1 | ||
| 15 | 2.5 | 1 | ||
| 13 | 2.5 | 1 | ||
| 14 | 3 | 0 | 0 |
In which of the following processes, the bond order increases and paramagnetic character changes to diamagnetic one? [2023]
(2)
NO is paramagnetic with B.O = 2.5, is diamagnetic with B.O = 3.
Consider the following statements:
(A) molecule has a trigonal planar structure.
(B) Bond length of is shorter than .
(C) Isoelectronic molecules or ions have identical bond order.
(D) Dipole moment of is higher than that of water molecule.
Choose the correct answer from the options given below: [2023]
(A) and (B) are correct
(B) and (C) are correct
(C) and (D) are correct
(A) and (D) are correct
(2)
(A) has triangular pyramidal structure

(B)
(C) Isoelectronic molecules or ions have identical bond order.
(D) Dipole moment due to less electronegativity difference between H and S as compared to H and O.
Which of the following will exhibit maximum attraction to an applied magnetic field?
(4)
From the given statements, incorrect statements are:
I. H.O.M.O. of dioxygen is [H.O.M.O. = highest occupied molecular orbital]
II. L.U.M.O. of dinitrogen is [L.U.M.O. = lowest unoccupied molecular orbital]
III. Bond strength of
I, II and III
II only
II and III only
III only
(2)
Choose the correct option [true or false] for the following compounds
I) In molecule only bonds are present.
II) In molecule one bond and one bond is present.
III) molecule is paramagnetic if mixing is not operative.
IV) Correct order of dipole moment for chloromethanes is
TFTT
FTFF
TFTF
TFFF
(1)
I, III, IV are statements are Correct