Chemistry - Nuclear Chemistry

Question - 1

Initial mass of a radioactive element is 16 gm. How many grams of it would be left after 24 years if its half life is 8 years?

• A 8
• B 4
• C 2
• D 1

Question - 2

Proton is

• A nucleus of deuterium
• B Ionised hydrogen molecule
• C ionised hydrogen atom
• D an alpha particle

Question - 3

The radioactive isotope of hydrogen is known as

• A protium
• B deuterium
• C tritium
• D para-hydrogen

Question - 4

Which of the following is radioactive?

• A Li
• B Rb
• C Cs
• D Fr

Question - 5

Gamma rays are essentially

• B high speed electrons
• C high speed neutrons
• D high speed protons

Question - 6

An isotope of parent element is produced when it loses

• A an alpha particle
• B a beta particle
• C one alpha and two beta particles
• D one beta and two alpha particles

Question - 7

A photon of hard gamma-rays knocks a proton of  26Mg nuclues. The substance produced is

• A an isotope nucleus 25Na
• B an isobar nucleus 23Na
• C an isotope nucleus 26Na
• D an isobar nucleus 26Mg

Question - 8

Which one of the following atom will contain the least number of neutrons?

• A 235U
• B 238U
• C 239U
• D 240U

Question - 9

The isotope 40K transforms into the isotope 40Ca. What kind of radioactive decay occurs in this case?

• A k-electron capture
• B  $\alpha-decay$
• C $\beta-decay$
• D positron decay

Question - 10

initial mass of a radioactive element is 160 g. How many grams of it would be left after 24 years if its half-life period is 6 years?

• A 6
• B 8
• C 10
• D 40