Numerical
For $\mathrm{He}^{+}$, a transition takes place from the orbit of radius $105.8 \mathrm{pm}$ to the orbit of radius $26.45 \mathrm{pm}$. The wavelengt...
Consider a helium (He) atom that absorbs a photon of wavelength 330 nm. The change in the velocity (in cm s$$-$$1) of He atom after the photon absorpt...
The figure below is the plot of potential energy versus internuclear distance (d) of H2 molecule in the electronic ground state. What is the value of ...
Not considering the electronic spin, the degeneracy of the second excited state( n = 3) of H atom is 9, while
the degeneracy of the second excited sta...
In an atom, the total number of electrons having quantum numbers n = 4, |ml| = 1 and ms = –1/2 is
The atomic masses of He and Ne are 4 and 20 a.m.u., respectively. The value of the de Broglie wavelength
of He gas at –73oC is “M” times that of the d...
The maximum number of electrons that can have principal quantum number, n = 3, and spin quantum number, ms = − 1/2 , is
The work function
( φ )
of some metals is listed below. The number of metals which will show
photoelectric effect when light of 300 nm wavelength fall...
Find out the number of waves made by a Bohr electron in once complete revolution in its 3rd orbit?
What is the maximum number of electrons that may be present in all atomic orbitals with principal quantum number 3 and azimuthal quantum number 2?
MCQ (More than One Correct Answer)
For diatomic molecules, the correct statement(s) about the molecular orbitals formed by the overlap of two $2 p_{z}$ orbitals is(are)
The ground state energy of hydrogen atom is $$-$$13.6 eV. Consider an electronic state $$\psi $$ of He+ whose energy, azimuthal quantum number and mag...
Which of the following statement(s) is(are) correct regarding the root mean square speed (Urms) and average translational kinetic energy (Eav) of a mo...
Ground state electronic configuration of nitrogen atom can be represented by
The energy of an electron in the first Bohr orbit of H atom is -13.6 eV. The possible energy value(s) of the excited state(s) for electrons in Bohr or...
Decrease in atomic number is observed during
Which of the following statement(s) is (are) correct?
The sum of the number of neutrons and proton in the isotope of hydrogen is
An isotone of $${}_{32}^{76}Ge$$ is
Many elements have non-integral atomic masses because:
When alpha particles are sent through a thin metal foil, most of them go straight through the foil because
MCQ (Single Correct Answer)
Consider the Bohr's model of a one-electron atom where the electron moves around the nucleus. In the following List-I contains some quantities for the...
Consider the Bohr's model of a one-electron atom where the electron moves around the nucleus. In the following List-I contains some quantities for the...
For $$H{e^ + }$$ ion, the only INCORRECT combination is
For hydrogen atom, the only CORRECT combination is :
For the given orbital in Column 1, the only CORRECT combination for any hydrogen-like species is :
P is the probability of finding the 1s electron of hydrogen atom in a spherical shell of infinitesimal thickness, dr, at a distance r from the nucleus...
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [$$\alpha_0$$ is Bohr radius]
The hydrogen like species Li2+ is in a spherically symmetric state S1 with one radial node. Upon absorbing light the ion undergoes transition to a sta...
The hydrogen like species Li2+ is in a spherically symmetric state S1 with one radial node. Upon absorbing light the ion undergoes transition to a sta...
The hydrogen like species Li2+ is in a spherically symmetric state S1 with one radial node. Upon absorbing light the ion undergoes transition to a sta...
Match the entries in Column I with the correctly related quantum number(s) in Column II. Indicate your answer by darkening the appropriate bubbles of ...
STATEMENT - 1 : The plot of atomic number (y-axis) versus number of neutrons (x-axis) for stable nuclei shows a curvature towards x-axis from the line...
According to Bohr's theory
En = Total energy, Kn = Kinetic Energy, Vn = Potential Energy, rn = Radius of nth orbit
Match the following
Column I
(A) ...
The number of radial nodes of 3s and 2p orbitals are respectively
The radius of which of the following orbit is same as that of the first Bohr's orbit of hydrogen atom?
Rutherford's experiment, which established the nuclear model of the atom, used a beam of
If the nitrogen atom has electronic configuration 1s7, it would have energy lower than that of the normal ground state configuration 1s22s22p3, becaus...
The wavelength associated with a golf ball weighing 200 g and moving at speed of 5 m/h is of the order
The quantum numbers +1/2 and -1/2 for the electron spin represent
The number of nodal planes in a px orbital is
The electronic configuration of an element is 1s2, 2s2 2p6, 3s2 3p6 3d5, 4s1 This represents its...
The electrons, identified by quantum numbers n and l, (i) n = 4, l = 1, (ii) n = 4, l = 0, (iii) n = 3, l = 2 and (iv) n = 3, l = 1 can be placed in o...
The orbital diagram in which the Aufbau principle is violated is
ASSERTION:
Nuclide $${}_{13}^{30}Al$$ is less stable than $${}_{20}^{40}Ca$$
REASON:
Nuclides having odd number of protons and neutrons are generally ...
For a d-electron the orbital angular momentum is
The orbital angular momentum of an electron in 2s orbital is
A 3p orbital has
Which of the following relates to photons both as wave motion and as a stream of particles?
Which of the following does not characterise X-rays?
The correct set of quantum numbers for the unpaired electron of chlorine atom is
The correct ground state electronic configuration of chromium atom is
The triad of nuclei that is isotonic is
The wavelength of a spectral line for an electronic transition is inversely related to :
The outermost electronic configuration of the most electronegative element is
Rutherford's alpha particle scattering experiment eventually led to the conclusion that:
The ratio of the energy of a photon of 2000Å wavelength to that 4000Å radiation is
Which one of the following sets of quantum numbers represents an impossible arrangement?
Bohr Model can explain
The radius of an atomic nucleus is of the order of
Electromangnetic radiation with maximum wavelength is:
Correct set of four quantum numbers for the valence (outermost) electron of rubidium (Z = 37) is
The increasing order (lowest first) for the values of e/m (charges/mass) for electron (e), proton (p), neutron (n) and alpha particle ($$\alpha$$) is...
Which electronic level would allow the hydrogen atom to absorb a photon but not to emit a photon?
Any p-orbital can accommodate upto
The principal quantum number of an atom is related to the
Rutherford's scattering experiment is related to the size of the
Rutherford's experiment on scattering of $$\alpha-particles$$ showed for the first time that the atom has
The number of neutrons in dipositive zinc ion with mass number 70 is
Subjective
Find the velocity (ms-1) of electron in first Bohr's orbit of radius a0. Also find the de Broglie's wavelength (in m). Find the orbital angular momen...
(a) The Schrodinger wave equation for hydrogen atom is
$$$\psi = {1 \over {4\sqrt {2\pi } }}{\left( {{1 \over {{a_0}}}} \right)^{3/2}}\left( {2 - {{{...
A ball of mass 100 g is moving with 100 ms-1. Find it's wavelength.
Wavelength of high energy transition of H-atoms is 91.2 nm. Calculate the corresponding wavelength of He atoms.
Calculate the energy required to excite one litre of hydrogen gas at 1 atm and 298 K to the first excited state of atomic hydrogen. The energy for the...
Calculate the wave number for the shortest wavelength transition in the Balmer series of atomic hydrogen.
Consider the hydrogen atom to be a proton embedded in a cavity of radius a0 (Bohr radius) whose charge is neutralised by the addition of an electron t...
Iodine molecule dissociates into atoms after absorbing light of 4500 Å. If one quantum of radiation is absorbed by each molecule, calculate the kineti...
Estimate the difference in energy between 1st and 2nd Bohr orbit for a hydrogen atom. At what minimum atomic number, a transition from n = 2 to n = 1 ...
What transition in the hydrogen spectrum would have the same wavelength as the Balmer transition n = 4 to n = 2 of He+ spectrum?
According to Bohr's theory, the electronic energy of hydrogen atom in the nth Bohr's orbit is given by $${E_n} = {{ - 21.6 \times {{10}^{ - 19}}} \ove...
Give reasons why the ground state outermost electronic configuration of silicon is:
...
The electron energy in hydrogen atom is given by E = (-21.7 $$\times$$ 10-12)/n2 ergs. Calculate the energy required to remove an electron completely ...
Calculate the wavelength in Angstrom of the photon that is emitted when an electron in the Bohr orbit, n = 2 returns to the orbit, n = 1 in the hydrog...
The energy of the electron in the second and the third Bohr's orbits of the hydrogen atom is -5.42 $$\times$$ 10-12 erg and -2.41 $$\times$$ 10-12 erg...
Fill in the Blanks
The outermost electronic configuration of Cr is _______.
The light radiations with discrete quantities of energy are called ______.
Wave functions of electrons in atoms and molecules are called ______.
The 2px, 2py and 2pz orbitals of atom have identical shapes but differ in their _____.
The uncertainty principle and the concept of wave nature of matter were proposed by ______ and ______ respectively. (Heisenberg Schrodinger, Maxwell, ...
Elements of the same mass number but of different atomic numbers are known as ____.
The mass of a hydrogen atom is ______ kg.
Isotopes of an element differ in the number of ______ in their nuclei.
When there are two electrons in the same orbital, they have _____ spins.
True or False
In a given electric field, $$\beta-particles $$ are deflected more than $$\alpha-particles$$ in spite of $$\alpha-particles$$ having larger charge.
The electron density in the XY plane in 3dx2 - y2 orbital is zero
Gamma rays are electromagnetic radiations of wavelengths of 10-6 to 10-5 cm
The energy of the electron in the 3d-orbital is less than that in the 4s-orbital in the hydrogen atom.
The outer electronic configuration of the ground state chromium atom is 3d4 4s2