(A) 1%
(B) 10%
(C) 0.1%
(D) 99%
Author:
λ × T1/2:
(A) 0.963
(B) loge1/2
(C) loge2
(D) A and C
If 15/16 of radioactive atoms decays in 16hrs, the half-life of elements is:
(A) 16 hrs.
(B) 8 hrs.
(C) 4 hrs.
(D) 2 hrs.
Different radioactive materials have:
(A) Same half-life
(B) Same total life
(C) different half-life
(D) both B & C
In radioactivity, the rate of decay:
(A) Can be increased by magnetic field
(B) Can be kept constant by the electric field
(C) Can be decreased by the field
(D) Is not effected by electric and magnetic field
A substance reduces to one sixteenth of its original mass in 2 hours. The half-life period of the substance will be:
(A) 30 min
(B) 90min
(C) 45min
(D) 60min
The half-life of 239U in minutes:
(A) 4.5×10 Power9
(B) 3.8
(C) 23.4
(D) none of them
In the Spectrum of hydrogen atom, the ratio of the longest wavelength in the Lyman series to the longest wavelength in the Balmer series:
(A) 9 / 5
(B) 3 / 2
(C) 5 / 27
(D) 4 / 9