1. According to Bohr’s atomic model

a. Each orbit has fixed energy, so each orbit is called sub-energy level
b. The energy of the electron is inversely proportional to its distance from the nucleus
c. Light is absorbed when an electron jumps a lower energy orbit
d. The farther the electron is from the nucleus, the more energy it has

2. Chlorine has two isotopes, both of which have

a. same mass number
b. same number of neutrons
c. different number of protons
d. same number of electrons

3. Number of neutrons in M having atomic no 13 and mass number 27 is

a. 13
b. 14
c. 27
d. 15

4. Which isotope is commonly used to irradiate cancer cells

a. Iodine-123
b.Carbon-14
c. Cobalt-60
d. Iodine-131

5. M shell has subshells

a. 1s 2s
b.2s 2p
c. 3s 3p 3d
d. 1s 2s 3s

6. A subshell that can accomodate 6 electrons is

a. s
b.p
c. d
d. f

7. Na-11 has electronic configuration

a. 1s2 2s2 3s1
b.1s2 2s2 2p5
c. 1s2 2s2 2p5 3s2
d. 1s2 2s2 2p6 3s1

8. Rutherford used ….particles in is experiment

a. He atoms
b. He⁺
c. He²⁺
d. He^2-

9. Which statement is not correct about isotopes

a. they have same atomic number
b. they have same chemical properties
c. they have same number of protons
d. they have same physical properties

10. Which isotope is used in nuclear reactors

a. U-234
b. U-238
c. U-235
d. all of these