The electronic configuration of element with atomic number 24 is :

1s², 2s² 2p⁶, 3s² 3p⁶ 3d⁴, 4s²
1s², 2s² 2p⁶, 3s² 3p⁶ 3d¹⁰
1s², 2s² 2p⁶, 3s² 3p⁶ 3d⁶
1s², 2s² 2p⁶, 3s² 3p⁶ 3d⁵, 4s¹

Solution

Electronic configuration of element with atomic no 24 is

1s², 2s², 2p⁶, 3s², 3p⁶, 4s¹, 3d⁵

Exactly half filled d-orbital has extra stability.

What is the correct orbital designation of an electron with the quantum number, n = 4, l = 3, m = –2, s = 1/2 ?

Solution

n = 4 represents 4th orbit

l = 3 represents f subshell

m = –2 represents orientation of f-orbital

s = 1/2 represents direction of spin of electron.

∴ The orbital is 4f.

The energy ratio of a photon of wavelength 3000Å and 6000Å is :

1 : 1
2 : 1
1 : 2
1 : 4

Solution

E = hv = h^c⁄_λ

So, E ∝ ¹⁄_λ

λ₁: λ₂ = 3000 A : 6000 A = 1 : 2

Hence, E₁ : E₂ = 2 : 1

The angular speed of the electron in n^th orbit of Bohr hydrogen atom is

Directly proportional to n
Inversely proportional of √n
Inversely proportional to n²
Inversely proportional to n³

Solution

Angular speed is ^V⁄_r. V_n ∝ ¹⁄_n and r_n ∝ n².

∴ Angular speed is inversely proportional to n

The number of d-electrons retained in Fe²⁺ (At.no. of Fe = 26) ion is

Solution

Fe⁺⁺ (26 – 2 = 24) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰ 3d⁶ hence no.of delectrons retained is 6. [Two 4s electron are removed]

The orientation of an atomic orbital is governed by

Spin quantum number
Magnetic quantum number
Principal quantum number
Azimuthal quantum number

Solution

Magnetic quantum no. represents the orientation of atomic orbitals in an atom. For example p_x, p_y & p_z have orientation along X-axis, Y-axis & Z-axis

The uncertainties in the velocities of two particles, A and B are 0.05 and 0.02 ms^–1 respectively.The mass of B is five times to that of the mass of A. What is the ratio of uncertainties ^Δx_A⁄_{Δx_B} in their positions ?

2
0.25
4
1

Solution

The orbitals are called degenerate when

they have the same wave functions
they have the same wave functions but different energies
they have different wave functions but same energy
they have the same energy

Solution

The orbitals which have same energy are called degenerate orbitals eg. p_x, p_y and p_z.

The order of filling of electrons in the orbitals of an atom will be

3d, 4s, 4p, 4d, 5s
4s, 3d, 4p, 5s, 4d
5s, 4p,3d, 4d, 5s
3d, 4p, 4s, 4d, 5s

Solution

The number of spherical nodes in 3p orbitals are

one
three
two
None of these

Solution

No. of radial nodes in 3p-orbital = (n – l – 1)

[for portbital l = 1]

= 3 – 1 – 1 = 1

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete