CBES Board Class 9 MCQ Quiz Hub

1. If n = 3 we are in
K shell
L shell
M shell
F shell

2. Water that contains H-2 atoms is called
heavy water
light water
pure water
chlorinated water

3. Electron revolves around the nucleus in orbits which have
variable energy
fixed energy
infinite energy
zero energy

4. In Rutherfords experiment ? particles were deflected because of
electrostatic repulsion between ? particles and positively charged part of atom
electrostatic repulsion between ? particles and positively charged part of atom
electrostatic repulsion between ? particles and positively charged part of atom
electrostatic attraction between ? particles and positively charged part of atom

5. The energy of an electron in orbit is proportional to
distance between shells
distance from nucleus
distance between two nuclei
positive charge inside nucleus

6. According to Rutherford most of the space occupied by the atom is
filled
partially filled
empty
none of above

7. The electronic configuration is the arrangement of electrons in
nucleus
shells
sub-shells
all of above

8. Electrons revolve only in those orbits with angular momentum as an
half integral multiple of h
integral multiple of h
integral multiple of h ? 2?
half integral multiple of 2?

9. After 3s the sub-shell begin to fill is
3p
3d
3f
4s

10. When an electron jumps from lower orbit to higher orbit
light is emitted
electrons are emitted
electrons are absorbed
light is absorbed

11. The lowest energy orbital among the following is
3h
2p
3s
3p

12. When Uranium-238 emits ? particles it decays in to
Helium
Carbon
Thorium-234
Uranium-235

13. D sub-shell can accommodate maximum
2 electrons
10 electrons
14 electrons
6 electrons

14. Chlorine-35 exists in nature about
0.35
0.4
0.5
0.75

15. Protium has
one neutron
two neutrons
no neutron
3 neutrons

16. ? particles are
positively charged
doubly positively charged
negatively charged
doubly negatively charged

17. The energy of emitted light is equal to
sum of energy levels
difference between energies of orbits
product of energies of orbits
none of above

18. Atoms having same atomic number but different atomic mass are called
derivatives
isotopes
elements
isomers

19. Rutherford bombarded thin gold foil with
? particles
? particles
? particles
neutrons

20. Iodine-123 is used to
diagnose thyroid problem
image the brain
kill cancer cells
trace the blood flow