CBSE Class 9 Science Journey Inside the Atom (Class 9 NCERT New) Quiz 14

1. The atomic number of Sulphur (S) is 16. Identify the number of electrons in each shell ofSulphur.

A (a)2, 8, 6 B (b)2, 8, 8 C (c)2, 2, 8, 4 D (d)2, 4, 8, 2

2. Which elements have a valency of 2?

A (a) Be and Si B (b) Si and Cl C (c) Be and O D (d) Cl and O

3. Which element would be inert in nature?

A (a) Element with 2 electrons B (b) Element with 9 electrons C (c) Element with 12 electrons D (d) Element with 20 electrons

4. The image shows the scientific notation of sodium. What is the atomic mass of Na?

A (a)11 B (b)12 C (c)23 D (d)34

5. Which isotope is used in the nuclear power plants to generate electricity?

A Uranium 235 B Iodine 131 C Cobalt 60 D Uranium 238

6. Who discovered the electron?

A Rutherford B Chadwick C Thomson D Goldstein

7. What was the source of alpha particles in Rutherford scattering experiment?

A Hydrogen nucleus B Argon nucleus C Helium nucleus D None of these

8. Why was the Thomson’s Model of an atom failed?i. It could not explain the screening of negative charges from that of positiveii. It did not tell about the presence of electronsiii. It did not give an idea about the discrete energy levelsiv. It explained the atom as a whole to be electrically neutral.

A Only (iii) B Both (i) & (iii) C Only (i) D Only (i)

9. What property of an element determines its chemical behaviour?

A Size of an element B Valency of an element C Molar mass of the element D None of these

10. Which of the following does not match the characteristics of an Isotope?

A Isotopes of some elements are radioactive B Isotopes are the atoms of different elements C Isotopes differ in number of neutrons D Isotopes differ in number of neutrons