2022
Q1
NEET
MCQ
10 Mar 2026
The half life of a first order reaction is 2000 years. If the concentration after 8000 years is 0.02 M, then the initial concentration was :
A.
0.04 M
B.
0.16 M
C.
0.32 M
D.
0.08 M
2018
Q2
AIIMS
MCQ
10 Mar 2026
A gas ‘X’ is used in filling balloons for meteorological observations. It is also used in gas-cooled nuclear reactors. Here, the gas X is
A.
neon
B.
argon
C.
krypton
D.
helium
2005
Q3
NEET
MCQ
10 Mar 2026
A nuclide of an alkaline earth metal undergoes radioactive decay by emission of the periodic table to which the resulting daughter element would belong is
A.
Gr.13
B.
Gr. 17
C.
Gr. 14
D.
Gr. 16
2004
Q4
NEET
MCQ
10 Mar 2026
The radioactive isotope ${}_{27}^{60}$Co which is used in the treatment of cancer can be made by (n.p) reaction. For this reaction the tarfet nucleus is
A.
$_{28}^{59}$ Ni
B.
$_{27}^{59}$ Co
C.
$_{28}^{60}$ Ni
D.
$_{27}^{60}$ Co
2003
Q5
NEET
MCQ
10 Mar 2026
The radioistope, tritium (${}_1^3$H) has a half-life of 12.3 years. If the initial amount of tritium is 32 mg, how many milligrams of it would remain after 49.2 years?
A.
1 mg
B.
2 mg
C.
4 mg
D.
8 mg
2002
Q6
NEET
MCQ
10 Mar 2026
${}_{92}^{235}$U, nucleus absorbs a neutron and distintegrate in ${}_{54}^{139}$Xe, ${}_{38}^{94}$Sr and $x$ so, what will be product $x$?
A.
3-neutrons
B.
2-neutrons
C.
$\alpha $-particle
D.
$\beta $-particle
2001
Q7
NEET
MCQ
10 Mar 2026
A human body required 0.01 m activity of radioactive substance after 24 hours. Half life of radioactive substance is 6 hours. Then inhection of maximum activity of radioactive substance that can be injected is
A.
0.08
B.
0.04
C.
0.16
D.
0.32
2001
Q8
NEET
MCQ
10 Mar 2026
If a ${}_b^aX$ species emits first a position, then two a and two b particles and in the last, one a, is also emitted and gets converts to ${}_d^c$Y species. So correct relation is
A.
c = a $-$ 12, d = b $-$ 5
B.
c = a $-$ 5, d = b $-$ 1
C.
c = a $-$ 6, d = b $-$ 0
D.
c = a $-$ 4, d = b $-$ 2
2000
Q9
NEET
MCQ
10 Mar 2026
A 300 grams radioactive sample at initial half life is 3 hours. After 18 hours remaining quantity
A.
4.68 gram
B.
2.34 gram
C.
3.34 gram
D.
9.37 gram