21 Electronic Structure of AtomsThe electronic structure of an atom describes the arrangement of electrons in different energy levels (shells) and sublevels (orbitals) around the nucleus. Electrons occupy energy levels in order of increasing energy, following the Aufbau principle, Pauli exclusion principle, and Hund’s rule. The distribution follows the pattern 1s² 2s² 2p⁶ 3s² 3p⁶, and so on, filling orbitals based on their energy hierarchy. This structure determines an element’s chemical properties and bonding behavior. 1 / 35The principal quantum number (nnn) determines: The shape and orientation of orbitals enery levels The spin of the electron The number of electrons in an atom 2 / 35The angular momentum of an electron in Bohr’s model is quantized and given by L=nh L=nh2 L=nh3 L=n2hL=n2h 3 / 35Which postulate of Bohr’s model explains the stability of an atom Electrons move in quantized orbits without radiating energy Electrons continuously lose energy and spiral into the nucleus Energy levels are non-quantized Electrons jump randomly between orbits 4 / 35Which scientist explained the hydrogen spectrum using the quantum model? Newton Bohr Einstein Maxwell 5 / 35What is the principal quantum number (n) for the first excited state of a hydrogen atom? 0 1 2 3 6 / 35The radius of the first Bohr orbit (n=1) in hydrogen is approximately: 0.53 nm 1.06nm 2.03nm 0.78nm 7 / 35. If n=3, what are the possible values of l 0, 1, 2, 3 0, 1, 2 1, 2, 3 -3 to +3 8 / 35The number of orbitals in a given subshell is determined by n 2l+1 l ml 9 / 35The energy levels of an electron in a hydrogen atom are given by which equation? En=−13.6/n2 eV En=−13.6/n eV En=−n/ 13.6 eV none 10 / 35The principal quantum number (nnn) can have values: Any integer Any positive integer Any real number even numbers only 11 / 35The line spectrum of an element is Unique for each element The same for all elements A continuous spectrum Independent of the element’s structure 12 / 35Which of the following is a direct consequence of the uncertainty principle? The exact path of an electron cannot be determined The speed of light changes in different media Particles do not have mass The energy of an atom remains constant 13 / 35The uncertainty principle is a fundamental concept in Classical mechanics Newtonian physics Quantum mechanics Electromagnetism 14 / 35If the intensity of incident light increases, what happens to the number of photoelectrons emitted increased decreased remains constant stops completly 15 / 35According to Bohr’s model, electrons in an atom move in Spiral orbits Elliptical orbits Stationary circular orbits Random paths 16 / 35What is the maximum number of electrons that can fit in the n=5 energy level 32 50 100 125 17 / 35Quantum numbers describe The energy levels in an atom The shape and orientation of orbitals The spin of electrons all of above 18 / 35What is the energy of an electron in the first (ground) state of a hydrogen atom? -13.3 eV 13.3eV -3.4 eV 3.4 eV 19 / 35If l=2 what are the possible values of ml -2, -1, 0, +1, +2 0, 1, 2 -1, 0, +1 -3 to +3 20 / 35Which set of quantum numbers is not valid n=3,l=2,ml=−2,ms=+1/2 n=2,l=2,ml=0,ms=−1/2 n=4,l=3,ml=+2,ms=−1/2 all are correct 21 / 35Line spectra are produced due to Continuous radiation from a hot body Absorption of light by a medium Excited atoms emitting specific wavelengths of light Scattering of light by small particles 22 / 35Who explained the photoelectric effect using quantum theory Newton Hugens Maxwell Einstein 23 / 35The lowest possible energy state of an electron in an atom is called: excited state valence state ground state Ionized state 24 / 35Heisenberg’s Uncertainty Principle states that Position and velocity of a particle can be measured simultaneously with infinite precision Position and momentum of a particle cannot be measured simultaneously with absolute precision Energy and mass of a particle cannot be measured simultaneously Time and distance of a particle cannot be measured simultaneously 25 / 35Bohr’s model was successful in explaining Hydrogen spectrum only All atomic spectra The structure of all elements Quantum mechanics 26 / 35The spectral lines in hydrogen's emission spectrum are grouped into different series. The series in the visible region is called Lyman series Balmer series Paschen series Brackett series 27 / 35The total number of orbitals in the third energy level (n=3n=3n=3) is 3 4 9 7 28 / 35The photoelectric effect is the phenomenon in which: Light is scattered by small particles Electrons are emitted from a metal surface when light falls on it Light bends around obstacles Light splits into different colors 29 / 35When an electron jumps from a higher energy level to a lower one, it: Absorbs a photon Emits a photon Gains energy Remains in the same state 30 / 35The quantum numbers n=4,l=2n = 4, l = 2n=4,l=2 correspond to which subshell 4s 3d 4d 4p 31 / 35When an electron moves from n=3n=3n=3 to n=2n=2n=2, it emits a photon in which spectral series? Lyman Balmer series Brackett series pfund series 32 / 35Which quantum number represents the orientation of orbitals n l m s 33 / 35Builiding up rule is called aufbau rule pauli's exclusion Hund's rule Heinsenberg rule 34 / 35The minimum energy required to remove an electron from a metal surface is called Kinetic energy Work function Potential energy Threshold frequency 35 / 35What is the minimum uncertainty in the momentum of a particle if its position uncertainty is zero zero infinite equal to mass Cannot be determined Your score isThe average score is 76% 0% Restart quiz
