In the decay sequence: U 92 238 → - x 1 Th 90 234 → - x 2 Pa 91 234 → - x 3 Z 234 → - x 4 Th 90 234 x 1 , x 2 , x 3 and x 4 are the particles/ radiation emitted by the respective isotopes. The correct option(s) is/are:

x 1 will deflect towards the negatively charged plate.

MEDIUM

Earn 100

Derive an expression for the decay constant of a radioactive substance.

Important Questions on Energy

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

Draw the curve showing the variation of binding energy per nucleon as a function of mass number

A

. Explain the stability of nucleus from the curve

HARD

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

Define the term ‘decay constant’ of a radioactive sample. The rate of disintegration of a given radioactive nucleus is

10000

disintegrations and

5, 000

disintegrations after

20 h o u r

. and

30 h o u r

. respectively from start. Calculate the half-life and the initial number of nuclei at

t = 0

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

What is meant by half life of a radioactive substance? Write its relation with decay constant.

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

In the radioactive disintegration series

_{90}^{232} T h \to_{82}^{208} P b,

involving

α

and

β

decay, the total number of

α

and

β

particles emitted are

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

Consider, the radioactive disintegration

{}_{82}A^{210} \to B \to C \to {}_{82}D^{206}

The sequence of emission can be

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

^{227} A c

has a half-life of 22 years with respect to radioactive decay. The decay follows two parallel paths:

^{227} Ac \to^{227} T h

and

^{227} Ac \to^{223} F r

. If the percentage of the two daughter nuclides are

2.0

and

98.0

, respectively the decay constant (in

y e a r^{- 1}

) for

^{227} Ac \to^{227} T h

path is closest to

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

Predict the element resulting from two

α

decay, two consecutive

β

decay and one

γ

decay of

Th - 232

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

In the radioactive decay process

Question Image

1. A and B are isobars

2. A and D are isotopes

3. C and D are isobars

4. A and C are isotopes

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

The decay constant which is the reciprocal of the time duration for which the number of the atoms of radioactive substance falls to

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

If the quantity of a radioactive element is doubled, the rate of disintegration will

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

In the decay sequence:

${}_{92}^{238}U \overset{- x_{1}}{\to} {}_{90}^{234}{Th} \overset{- x_{2}}{\to} {}_{91}^{234}{Pa} \overset{- x_{3}}{\to} {}^{234}Z \overset{- x_{4}}{\to} {}_{90}^{234}{Th}$

$x_{1}, x_{2}, x_{3}$ and $x_{4}$ are the particles/ radiation emitted by the respective isotopes. The correct option(s) is/are:

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

A bacterial infection in an internal wound grows as

N^{'} (t) = N_{0} e x p (t)

, where the time

t

is in hours. A dose of antibiotic, taken orally, needs 1 hour to reach the wound. Once it reaches there, the bacterial population goes down as

\frac{d N}{d t} = - 5 N^{2}

. What will be the plot of

\frac{N_{0}}{N}

t

after

1

hour?

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

A nucleus

X

captures a

β

particle and then emits a neutron and

γ

ray to form

Y . X

and

Y

are:-

HARD

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

A and B are two substances undergoing radioactive decay in a container. The half life of A is

15 \min

and that of B is

5 \min

. If the initial concentration of B is

4

times that of A and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? ________min.

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

The ratio of the binding energies of three nuclei is

1 : 4 : 9

. If the ratio of their nuclear radii is

1 : 2 : 3

, the nuclei in the decreasing order of the stability can be arranged as

MEDIUM

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

{}_{93}^{239}{Np}

is a

β

-emitter, but the product is also radioactive and give

{}^{235}U

. Which particle(s) is/are emitted by the product?

EASY

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

Select the correct option

HARD

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

A radioactive sample is emitting

64

times radiations than non-hazardous limit. If its half life is

2 h

, after what time it become non hazardous?

HARD

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

{}_{92}^{238}U

is known to undergo radioactive decay to form

{}_{82}^{206}{Pb}

by emitting alpha and beta particles. A rock initially contained

68 \times 10^{- 6} g

{}_{92}^{238}U

. If the number of alpha particles that it would emit during its radioactive decay of

{}_{92}^{238}U

{}_{82}^{206}{Pb}

in three half-lives is

Z \times 10^{18}

, then what is the value of

Z

HARD

Chemistry>Physical Chemistry>Energy>Nuclear Fusion and Fission

In the nuclear transmutation

_{4}^{9} Be + X ⟶_{4}^{8} Be + Y

, identify

(X, Y)

Derive an expression for the decay constant of a radioactive substance.

Important Questions on Energy

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