A radioactive substance emits n beta particles in the first 2 s and 0.5 n beta
A radioactive substance emits n beta particles in the first 2 s and 0.5 n beta particles in the next 2 s. The mean life of the sample is
Options
(a) 4 s […]
Radioactivity
A uranium nucleus ₉₂ U ²³⁸ emits an α-particle and a β-particle in succession.
A uranium nucleus ₉₂ U ²³⁸ emits an α-particle and a β-particle in succession. The atomic number and mass number of the final nucleus will be
Options
(a) 90233 (b) 90238 (c) 91238 […]
A sample of radioactive element has a mass of 10 gram at an instant t=0.
A sample of radioactive element has a mass of 10 gram at an instant t=0. The approximate mass of this element in the sample after two mean lives is
Options
(a) 2.50 gram (b) […]
After 300 days, the activity of a radioactive sample is 5000 dps
After 300 days, the activity of a radioactive sample is 5000 dps (disintegration per second). The activity becomes 2500 dps after another 150 days. The initial activity of the sample (in dps) is
Options […]
A nucleus disintegrates into two nuclear parts which have their velocities in the ratio
A nucleus disintegrates into two nuclear parts which have their velocities in the ratio 2 : 1. The ratio of their nuclear sizes will be
Options
(a) 2¹/³ : 1 (b) 1 : 3¹/² […]
The half-life of a radioactive substance is 30 min. The time (in minutes) taken
The half-life of a radioactive substance is 30 min. The time (in minutes) taken between 40% decay and 85% decay of the same radioactive substance is
Options
(a) 15 (b) 30 (c) 45 […]
A radioactive substance decays to 1/16th of its initial activity in 40 days.
A radioactive substance decays to 1/16th of its initial activity in 40 days. The half-life of the radioactive substance expressed in days is
Options
(a) 2.5 (b) 5 (c) 10 (d) 20
Correct Answer: […]
If a nucleus ᴢXᴬ emits 9α and 5β-particles, then the ratio of total protons and neutrons
If a nucleus ᴢXᴬ emits 9α and 5β-particles, then the ratio of total protons and neutrons in the final nucleus is
Options
(a) (Z-13)/(A-36) (b) (Z-13)/(A-Z-13) (c) (Z-18)/(A-36) (d) (Z-13)/(A-Z-23)
Correct Answer:
(Z-13)/(A-Z-23)
The ionisation potential of hydrogen-atom is -13.6 eV. An electron in the groundstate
The ionisation potential of hydrogen-atom is -13.6 eV. An electron in the groundstate of a hydrogen-atom absorbs a photon of energy 12.75 eV. How many different spectral lines can one expect when the electron make […]
Radioactivity of a sample at T₁ time is R₁ and at time T₂ is R₂. If half-life
Radioactivity of a sample at T₁ time is R₁ and at time T₂ is R₂. If half-life of sample is T, then in time (T₂ – T₁), the number of decayed atoms is proportional to […]