Sub-atomic Particles & Models — Practice Questions
Free NEET Chemistry multiple-choice questions on Sub-atomic Particles & Models. Attempt each question and reveal the answer with a full explanation.
Based on the Rutherford -particle scattering experiment, which of the following conclusions is correct regarding the structure of the atom? The entire positive charge and most of the mass of the atom are concentrated in a very small region called the nucleus. The positive charge is uniformly distributed throughout the atom like a pudding. Electrons revolve around the nucleus in specific elliptical orbits with varying energy. The mass of the atom is evenly distributed across the entire volume of the atom. The number of protons, neutrons and electrons in 175 71 Lu , respectively, are 104, 71 and 71 71, 71 and 104 175, 104 and 71 71, 104 and 71 Identify the correct statement regarding the photoelectric effect. The kinetic energy of the emitted electrons depends on the frequency of incident light. The number of photoelectrons emitted is proportional to the frequency of light. Photoelectrons are emitted only if the frequency is less than threshold frequency. The kinetic energy of electrons is proportional to the intensity of light. If the stopping potential for a metal is 8.2 V when incident radiation of energy 12.4 eV is used, what is the work function of the metal? 4.2 eV 20.6 eV 8.2 eV 1.51 eV The threshold frequency for a metal is 7.0 10 14 s -1 . When light of frequency 1.0 10 15 s -1 hits the metal, the maximum kinetic energy of the emitted electrons is: 1.99 10 -19 J 6.63 10 -19 J 4.64 10 -19 J 1.10 10 -19 J The ratio of the specific charge ( e/m ) of a proton to that of an -particle is: 2 : 1 1 : 2 1 : 1 4 : 1 Which of the following statements about cathode rays is INCORRECT? The characteristics of cathode rays depend on the nature of the gas present in the tube. They start from cathode and move towards the anode. They travel in straight lines in the absence of an external field. They consist of negatively charged particles called electrons. Select the correct statements from the following A. Atoms of all elements are composed of two fundamental particles. B. The mass of the electron is 9.10939 × 10 -31 kg. C. All the isotopes of a given element show same chemical properties: D. Protons and electrons are collectively known as nucleons. E. Dalton’s atomic theory, regarded the atom as an ultimate particles of matter Choose the correct answer from the options given below A, B and C only C, D and E only A and E only B, C and E only The ratio of the specific charge ( e/m ) of an electron to that of an -particle (considering the mass of a proton to be 1836 times the mass of an electron) is approximately: 3672:1 1836:1 7344:1 1:1 The mass of an electron in atomic mass units (amu) is approximately: 0.00054 amu 1.008 amu 1.007 amu 0.54 amu The specific charge ( e/m ) of cathode rays is independent of: All of the above The nature of the gas present in the tube The material of the electrodes The potential difference applied between electrodes The mass of an electron is approximately equal to: 1/1837 of the mass of a hydrogen atom 1/12 of the mass of a carbon atom The mass of a neutron The mass of a positron In Rutherford's gold foil experiment, the scattering of h -particles is due to: Coulombic repulsion between the nucleus and h -particles The attraction between electrons and h -particles The collision of h -particles with neutrons Magnetic forces Which of the following pairs of nuclei are isotones? 14 30 Si and 15 31 P 6 14 C and 7 14 N 8 16 O and 8 18 O 1 3 H and 2 3 He The Millikan's oil drop experiment was used to determine which of the following properties of an electron? Charge of an electron Mass of an electron Specific charge ( e/m ) of an electron Velocity of an electron The number of electrons, protons, and neutrons in 33 75 As are respectively: 33, 33, 42 33, 42, 33 42, 33, 33 75, 33, 42 Which of the following subatomic particles was discovered by James Chadwick by bombarding beryllium with -particles? Neutron Proton Electron Positron According to Moseley, the frequency ( ) of the characteristic X-rays emitted by an element is related to its atomic number ( Z ) as: Z Z Z 2 2 Z