Nuclei MCQs For NEET

1 The helium atom does not contain

A two protons

B two electrons

C two neutrons

D six nucleons

View Answer

Answer:six nucleons

2 Energy of electron in the 1st orbit of H-atom is:

A -13.6 MeV

B -13.6 eV

C -13.6 J

D 13.6 J

View Answer

Answer:-13.6 eV

3 Mass is converted into energy according to the relation:

A E = me²

B E = mgh

C

D

View Answer

Answer:E = me²

4 The isotope generally used for the treatment of cancer is:

A I¹³¹

B Hg¹⁹⁷

C O¹⁵

D Co⁶⁰

View Answer

Answer:Co⁶⁰

5 Which of the following atoms has the lowest ionization potential?

A

B

C

D

View Answer

Answer:C

6 Half-lives of two radioactive substances A and B are respectively 20 minutes and 40 minutes. Initially the samples of A and B have equal number of nuclei. Find the ration of remaining number of A and B nuclei after 80 minutes.

A 1 : 1

B 4 : 1

C 1 : 4

D 1 : 16

View Answer

Answer:1 : 4

7 The binding energy per nucleon for the parent nucleus is E₁ and that for the daughter nuclei is E_2.Then

A E₁> E₂

B E₂> E₂

C E₁= 2E₂

D E₂= 2E₁

View Answer

Answer:E₂> E₂

8 In a sample off radioactive substance, what percentage decays in one mean life time?

A 70 %

B 63.2 %

C 45.8 %

D 23%

View Answer

Answer:63.2 %

9 The number of beta particles emitted by a radioactive substance is twice the number of alpha particles emitted by it. The resulting daughter is an

A isobar of parent

B isomer of parent

C isotone of parent

D isotope of parent

View Answer

Answer:isotope of parent

10 A radioactive nucleus ‘A’ undergoes a series of decays according to the following scheme :

class 12 physics chapter 13 nuclei

If the mass number and atomic number of A are 180 and 72 respectively then the mass number and atomic number for A₄ are

A 69 and 172 respectively

B 115 and 71 respectively

C 172 and 69 respectively

D None of these

View Answer

Answer:172 and 69 respectively

11 The half life period of a radioactive material if its activity drops to (1/16)th of its initial value in 30 years is

A 1.5 years

B 3.5 years

C 7.5 years

D 15 years

View Answer

Answer:7.5 years

12 There are 10⁶ radioactive nuclei in a given radioactive element. Its half life is 20 seconds. The number of nuclei will remain left after 10 seconds are:

A 3 × 10⁶

B 3 × 10⁵

C 7 × 10⁵

D 2 × 10⁵

View Answer