136. One of the fundamental particles is missing in one of the isotopes of hydrogen atom. The particle and isotope are respectively 1) Neutron, protium 2) Neutron, tritium 3) Proton, protium 4) Electron, tritium 137. The charge of an electron is 1.6 x 10-19 C what will be the value of charge on Na+ ion 1) 1.6 x 10-19 C 2) 3.2 x 10-19 C 3) 2.4 x 10-19 C 4) 10 x 1.6 x 10-19 C 138. Which of the following is correct for cathode rays in discharge tube 1) Independent of the nature of the cathode 2) Independent of the nature of the gas 3) Deflection is observed in presence of electric and magnetic field 4) All the above 139. The specific charge for a cathode ray 1) Has the smallest value when the discharge tube is filled with H2 2) Is constant 3) Varies with the atomic number of gas in the discharge tube 4) Varies with the atomic number of an element forming the cathode ray 140. The specific charge for positive rays is much less than the specific charge for cathode rays. This is because 1) Positive rays are positively charged 2) Charge on positive rays is less 3) Positive rays comprise ionised atoms whose mass is much higher 4) Experimental method for determination is wrong 141. If S1 be the specific charge (e/m) of cathode rays and S2 be that of positive ray then which is true ? 1) S1= S2 2) S1> S2 3) S1< S2 4) Any one of these 142. The massive particle among the following is 1) particle 2) Deuteron 3) Proton 4) particle 143. Which of the following statements about the electron is incorrect ? 1) It is a negatively charged particle 2) The mass of electron is equal to the mass of neutron 3) It is a basic constituent of all atoms 4) It is a constituent of cathode rays 144. Ernest Rutherford’s model of the atom didn’t specifically include the ____ 1) Proton 2) Electron 3) Nucleus 4) Neutron 145. The conclusions of Rutherford scattering experiment does not include 1) particle can come within a distance of the order of 10-14 m of the nucleus 2) The radius of the nucleus is less than 10-14m 3) Scattering follows Coulomb’s law 4) The (+) vely charged particles of an atom move with extremely high velocities 146. A neutrol atom, with atomic number greater than one consists of 1) Protons only 2) Protons and neutrons 3) Neutrons and electrons 4) Neutrons, electrons and protons 147. The ratio between the neutrons present in carbon atom and silicion atom with mass numbers 12 and 28 is 1) 7 : 3 2) 3 : 7 3) 1 : 2 4) 2 : 1 plz answer correctly and fast.... 148. Many elements have non - integral masses. This is because 1) Their isotopes have different atomic number 2) Their isotopes have different masses 3) Their isotopes have non - integral masses 4) Their constituents, protons, electrons and neutrons combine to give fractional masses 149. Among the following which is not isoelectronic with others 1) HF 2) H2O 3) NH3 4) CO
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