MHT-CET Structure of Atom — practice questions
90 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice MHT-CET Structure of Atom in the app →In a discharge tube, cathode rays travel from which electrode?Which British physicist discovered the electron in 1897?The mass of positive particles formed in a discharge tube depends on what?Millikan's oil drop work showed the charge on a droplet is alwaysThe smallest, lightest positive ion obtained from hydrogen was named theIn which year did Thomson propose his model of the atom?How did Thomson model the atom?Rutherford bombarded a thin foil of which metal with alpha particles?Most alpha particles passed straight through gold foil. This showed that the atom isAbout how many alpha particles in 20,000 bounced almost straight back?The radius of an atomic nucleus is aboutThe radius of an atom is of the order ofA key drawback of Rutherford's nuclear model was that itIn a neutral atom, the number of protons is equal to theProtons and neutrons in the nucleus are together calledWhich pair of species forms isobars?Isotopes of an element have the sameHow many neutrons does a deuterium nucleus contain?The chlorine isotope with mass number 35 and atomic number 17 has how many neutrons?An atom has 29 electrons and 35 neutrons. What is its mass number?A sodium atom has atomic number 11 and mass number 23. How many neutrons does it have?In which year did Niels Bohr put forward his model of the hydrogen atom?In Bohr's model, the angular momentum of an electron is an integral multiple ofWhat is the radius of the first Bohr orbit of hydrogen?Bohr's radius of the nth hydrogen orbit varies in proportion toBohr's model could not explain which observation?Bohr's model works well for hydrogen but fails forA well defined circular orbit contradicts which principle?In 1924 de Broglie proposed that matterWhich scientist is credited with the uncertainty principle?In quantum mechanics, an atomic orbital refers to theWhich three quantum numbers characterise an atomic orbital?Which quantum number mainly fixes the size of an orbital?The value of l for a p subshell isFor principal quantum number n = 3, the allowed values of l areHow many orbitals make up a d subshell?What does the azimuthal quantum number l determine?The magnetic quantum number ml gives information about theWhich letter denotes the shell with n = 3?All s orbitals have what kind of shape?A boundary surface usually encloses about what chance of finding the electron?Why can a boundary surface for 100 percent probability not be drawn?In a multi-electron atom, orbital energy depends onIn a hydrogen atom, the 2s and 2p orbitals haveWithin one shell of a multi-electron atom, subshell energy rises in the orderSubshells of one shell differ in energy in multi-electron atoms mainly because ofThe net positive charge felt by an outer electron is called theBy the (n + l) rule, which orbital has lower energy?2p and 3s both have n + l = 3. Which has lower energy, and why?The aufbau principle describes theAccording to the usual filling order, which orbital fills first?In potassium, the valence electron occupies which orbital?The exclusion principle of 1926 is credited toBy the Pauli principle, one orbital can hold at most how many electrons?Hund's rule says that in a subshell, electronsElectrons entering orbitals of equal energy have which spin arrangement as far as possible?What is the ground state configuration of sodium (Z = 11)?Half-filled and fully filled subshells gain extra stability fromElectrons in the completely filled inner shells are calledThe filling of the 3d orbitals begins with which element?In Planck's quantum theory, radiation energy is emitted inThe value of Planck's constant h isWho first observed the photoelectric effect in 1887?Who explained the photoelectric effect using the quantum idea of light?The SI unit hertz is equal to which of these?Wavenumber, used in spectroscopy, is the number ofLight from excited hydrogen atoms passed through a prism gives aRestricting a property to only discrete values is calledWhich instrument depends on the wave nature of electrons?In Rutherford's model, electrons are held to the nucleus byIn which species do all orbitals of a shell have equal energy?After s, p, d and f, the next subshell letter isThe glowing coating behind a perforated anode in a cathode ray tube isWhich scientist investigated cathode rays in 1897 and showed they are streams of negatively charged particles?Some alpha particles bouncing back from gold foil indicated what?Rutherford's 1919 work with fast alpha particles transmuted nitrogen into oxygen and released which species?Who predicted in 1920 that an electrically neutral massive particle must exist in the nucleus?In which year did James Chadwick discover the neutron?Chadwick found the neutron by studying protons knocked out of which substance by radiation from beryllium?How many neutrons does a nuclide of argon with mass number 40 and atomic number 18 contain?The total number of protons and neutrons in an atom is called its what?Which relation correctly connects mass number A, atomic number Z and neutron number N?What is the identity of an element decided by?An atom or nucleus with a unique composition specified by its Z and A is called a what?What do all isotopes of an element have in common?The German word 'Aufbau' in the aufbau principle means what?At which electron does pairing start in a p subshell, according to Hund's rule?Hund's rule applies to filling of electrons in orbitals of which kind?In the box notation for configurations, an up arrow and a down arrow in one box show what?A hydrogen atom electron has energy fixed by which quantum number alone?