AMUEEE Atomic Structure and Valency — practice questions
84 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice AMUEEE Atomic Structure and Valency in the app →The maximum number of electrons that can be accommodated in the $n$-th shell of an atom is:The four quantum numbers describing an electron in an atom are:
Hund's rule of maximum multiplicity states thatAccording to Heisenberg's uncertainty principle, $\Delta x \cdot \Delta p \geq$:Two electrons in the same orbital must have:Calculate the de Broglie wavelength of an electron moving at $10^6$ m/s. (Take $h = 6.6 \times 10^{-34}$ J·s, Bohr's first postulate: electrons revolve in ___ orbits around the nucleus.In Bohr's model, angular momentum of an electron in orbit n equals:Energy of electron in n-th orbit of hydrogen:Principal quantum number n indicates:Number of orbitals in subshell of azimuthal quantum number l:How many electrons can fit in a single orbital?Electron configuration of carbon (Z = 6):For hydrogen, wavelength emitted in n=3 to n=2 transition (Balmer):de Broglie wavelength of an electron with momentum p:Heisenberg uncertainty principle:Number of subshells in shell with n = 3:Electron configuration of nitrogen (Z = 7):Total number of electrons that can occupy shell with n = 4:Magnetic quantum number m_l for a 3d orbital can be:Wavelength of light needed to ionize hydrogen from ground state (13.6 eV):Radius of n-th Bohr orbit for hydrogen (a₀ ≈ 0.529 Å):Effective nuclear charge Z_eff for the 2p electron of carbon (using Slater's rules approximately):For He⁺ ion (1 electron, Z = 2), energy in ground state:The Pauli exclusion principle states that two electrons in an atom cannot have:Energy of the photon emitted in a hydrogen transition from n=4 to n=2:Number of nodes in a 3p orbital (n=3, l=1):For Bohr's hydrogen-like atom, what is the velocity of electron in n-th orbit (in terms of fine structure consPhotoelectric effect: when light of frequency ν falls on a metal of work function φ, KE of emitted electrons iThe wave number $\bar{\nu}$ of electromagnetic radiation is defined asIn vacuum, the velocity of electromagnetic radiation isA photon has wavelength $400\,nm$. Its frequency is approximatelyThe wave number of a photon of frequency $6 \times 10^{14}\,Hz$ (in vacuum) isAccording to Planck's quantum theory, energy is emitted or absorbed in discrete packets calledThe energy of a photon of wavelength $\lambda$ is given byA photon of wavelength $300\,nm$ has approximately what energy in eV? (Use $hc = 1240\,eV\,nm$.)In the photoelectric effect, the kinetic energy of the ejected electron depends onThe threshold frequency $\nu_0$ for a metal is the minimum frequencyLight of frequency $\nu = 2\nu_0$ ejects photoelectrons from a metal with threshold frequency $\nu_0$. The maxIn a photoelectric experiment, doubling the *intensity* of incident light (frequency unchanged) willRutherford's $\alpha$-particle scattering experiment used a thin foil of which metal?In Rutherford's experiment, the observation that a few $\alpha$-particles bounced *back* impliedThe radius of a nucleus of mass number $A$ is approximately $R = R_0 A^{1/3}$ with $R_0 = 1.33 \times 10^{-15}Bohr's postulate quantises the angular momentum of an electron in a stationary orbit asFor a hydrogen-like atom of nuclear charge $Z$, the radius of the $n$th Bohr orbit scales asThe energy of the $n$th Bohr orbit of a hydrogen-like atom isThe ratio of the radii of the third Bohr orbit of $He^+$ and the first Bohr orbit of $H$ isThe velocity of the electron in the $n$th Bohr orbit of a hydrogen-like atom is proportional toThe energy required to remove the electron from the first excited state ($n=2$) of $He^+$ isWhich series of the hydrogen spectrum lies entirely in the *visible* region?Rydberg's formula for the wave number of a hydrogen spectral line isWhen an electron in a hydrogen atom returns to the ground state from $n = 5$, the maximum number of distinct sThe longest wavelength line in the Lyman series of hydrogen corresponds to the transitionA hydrogen atom in its ground state absorbs a photon and is excited to $n = 4$. The number of *possible* spectThe de Broglie wavelength of a particle of mass $m$ and momentum $p$ isThe de Broglie wavelength of an electron in the $n$th Bohr orbit, in terms of the orbit radius $r_n$, isAn electron is accelerated through a potential difference of $100\,V$. Its de Broglie wavelength is approximatHeisenberg's uncertainty principle relates the uncertainties in position and momentum asThe minimum uncertainty in the velocity of an electron whose position is known to within $\Delta x = 0.1\,nm$ The principal quantum number $n$ can take valuesFor principal quantum number $n$, the orbital quantum number $l$ takes valuesFor orbital quantum number $l$, the magnetic quantum number $m_l$ takes valuesHow many orbitals are present in the $n = 3$ shell?The maximum number of electrons in the subshell with $n = 4, l = 2$ isWhich set of quantum numbers $(n, l, m_l, m_s)$ is **NOT** allowed?Hund's rule applies during the filling ofThe Aufbau principle dictates that orbitals fill in order of increasingWhich of the following orbital shapes is dumbbell-shaped along an axis?How many *angular* nodes does a $3d$ orbital have?The number of *radial* nodes in a $4s$ orbital isThe ionisation energy of hydrogen in its ground state isFor $He^+$, the ionisation energy from its ground state isWhich transition in the hydrogen atom emits the largest amount of energy?Which of the following experimental phenomena could **NOT** be explained by classical EM wave theory?The Bohr model failed to explainIn the photoelectric effect, the *stopping potential* $V_0$ varies with the frequency of incident light asWhich of the following is **NOT** a possible set of quantum numbers for a 3d electron?The total number of electrons that can fit in the $M$ shell ($n=3$) isThe Bohr radius for hydrogen ($n=1, Z=1$) is approximatelyThe proton was discovered through experiments involvingThe neutron was discovered byIn Thomson's atomic model (plum-pudding), the atom isThe Bohr orbit velocity of the ground-state electron in hydrogen is aboutThe Rydberg constant for hydrogen, in SI units, is