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The Structure of Atom Worksheet-5

The Structure of Atom Worksheet-5

 

  1. An element X has the same mass number and atomic number. This element is

(a) Inert gas                                  (b) Hydrogen

(c) Alpha particle                         (d) Helium

 

  1. John Dalton was the first to give us an idea about the structure of the atom.The main defect in Dalton’s atomic model is about

(a) Similarity of atoms of same element

(b) Differences in atoms of different elements

(c) Indivisibility of atom

(d) That atoms combine in small whole numbers

 

  1. Bombarding beryllium atom with alpha particles led to the discovery of:

(a) Electrons     (b) Protons        (c) Neutrons     (d) None of these

 

  1. Canal ray particles were found to have the least mass and charge when a particular element was used in the discharge tube. The element is:

(a) Oxygen        (b) Nitrogen      (c) Hydrogen    (d) Ozone

 

  1. Milliken’s oil drop experiment found out:

(a)  ratio of electron               (b) Charge of electron

(c) Mass of the electron              (d) Velocity of an electron

 

  1. A neutral atom of element has a nucleus with a nuclear charge 13 times and mass 27 times that of hydrogen nucleus. What is the ratio of electrons to protons in its stable positively charged ion.

(a) 27 : 13          (b) 10 : 15          (c) 20 : 26         (d) 10 : 14

 

  1. The number of neutrons present in an atom of hydrogen is

(a) 0                   (b) 1                    (c) 2                    (d) None of these

 

  1. The most important outcome of the Thomsons atomic model is :

(a) Idea about the Nucleus

(b) Idea about neutrons

(c) The electrical neutrality of the atom

(d) None of these

 

  1. Some of the elements have fractional atomic masses. The reason for this could be:

(a) The existence of isobars

(b) The existence of isotopes

(c) The nuclear reactions

(d) The presence of neutrons in the nucleus

 

  1. Which of these pairs has almost similar masses?

(a) Proton-Electron                  (b) Neutron-Electron

(c) Electron-1H1                                 (d) Neutron-1H1

 

Answer Key:

(1)-(b); (2)-(c); (3)-(c); (4)-(c); (5)-(b); (6)-(c); (7)-(a); (8)-(c); (9)-(b); (10)-(d)