List of top Chemistry Questions on Atomic Structure

An element has two isotopes having atomic masses 10 and 15 u, respectively. If the percent abundance of lighter isotopes is 80%, then the average atomic mass of the element is:

Which of the following molecules has a trigonal planar molecular geometry?

Which of the following represents the wavelength of spectral line of Balmer series of He$^+$ ion? (R = Rydberg constant, n $>$ 2)

Identify the set containing isoelectronic species.

The period and group numbers of the element having maximum electronegativity in the long form of periodic table, respectively, are

The total maximum number of electrons possible in 3d, 6d, 5s and 4f orbitals with $m_l$ (magnetic quantum number) value -2 is

In an element with atomic number (Z) 25, the number of electrons with (n + l) value equal to 3 and 4 are x and y respectively. The value of (x + y) is

In Am$^{3+}$ (Z = 95), the number of f-electrons with ($n + \ell$) value equal to 8 is (where $n$, $\ell$ represent principal and azimuthal quantum numbers)

The orbital with number of total nodes as 3 and angular nodes as 3 is

Match the following

The ratio of wavelengths of first line ($ n_2 = 3 $) and second line ($ n_2 = 4 $) of Balmer series of hydrogen spectrum is

Choose the incorrect statement from the following:

The ratio of wavelengths of first line ($ n_2 = 3 $) and second line ($ n_2 = 4 $) of Balmer series of hydrogen spectrum is

The number of d-electrons in Fe²⁺ (Z = 26) is not equal to:

Which element has the smallest atomic radius among the following?

Which of the following has the highest ionization energy?

Energy and radius of first Bohr orbit of He$^+$ and Li$^2+$ are:
Given: $ R_H = 2.18 \times 10^{-18} \, \text{J}, a_0 = 52.9 \, \text{pm} $

The ratio of the wavelengths of the light absorbed by a Hydrogen atom when it undergoes n = 2 $\rightarrow$ n = 3 and n = 4 $\rightarrow$ n = 6 transitions, respectively, is:

The element having $[Ar]3d^{10}4s^1$ electronic configuration is

Which of the following is/are correct with respect to the energy of atomic orbitals of a hydrogen atom?
(A) $ 1s<2s<2p<3d<4s $
(B) $ 1s<2s = 2p<3s = 3p $
(C) $ 1s<2s<2p<3s<3p $
(D) $ 1s<2s<4s<3d $
Choose the correct answer from the options given below:

Match the following:

The extra stability of half-filled subshell is due to
(A) Symmetrical distribution of electrons
(B) Smaller coulombic repulsion energy
(C) The presence of electrons with the same spin in non-degenerate orbitals
(D) Larger exchange energy
(E) Relatively smaller shielding of electrons by one another
Identify the correct statements

For electron in '2s' and '2p' orbitals, the orbital angular momentum values, respectively are :

Which one of the following about an electron occupying the 1 s orbital in a hydrogen atom is incorrect ? (Bohr's radius is represented by $\mathrm{a}_{0}$ )

Which of the following postulate of Bohr's model of hydrogen atom in not in agreement with quantum mechanical model of an atom ?