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.

A radioactive element ' A ' decays as follows: A ⟶ 3 0 min B + 2 He 4 B ⟶ 2 days C + 2 e - 1 0 Which of the following statements is/are incorrect?

Maximum amount of ' B ' present at any time is less than half of initial amount of ' A ' .

Atomic number of ' A ' and ' C ' are same.

After two hours less than 10 % of the initial ' A ' is left.

HARD

Earn 100

Which of the following statements are incorrect:

50% studentsanswered this correctly

Important Questions on Nuclear Chemistry

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

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:

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

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

HARD

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

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>Nuclear Chemistry>Theory of Radioactive Disintegration

{}_{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

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

Predict the element resulting from two

α

decay, two consecutive

β

decay and one

γ

decay of

Th - 232

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

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>Nuclear Chemistry>Theory of Radioactive Disintegration

A nucleus

X

captures a

β

particle and then emits a neutron and

γ

ray to form

Y . X

and

Y

are:-

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

Consider, the radioactive disintegration

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

The sequence of emission can be

HARD

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

In the nuclear transmutation

_{4}^{9} Be + X ⟶_{4}^{8} Be + Y

, identify

(X, Y)

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

A certain substance decays to

\frac{1}{32}

of its initial activity in 25 days. The half life is

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

A drug has radioactivity 80 dpm and after 20 minutes after its activity is 40 dpm. The number of atoms present initially were.

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

A sample of radioactive substance shows an intensity of 2.3 milli Ci at a time t and an intensity of 1.62 milli Ci after 600 s. The half-life period of the radioactive metal is

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

The half life of

^{238} U

for

α

-decay is

4.5 \times 10^{9}

years. The number of disintegrations per second occur in 1g of

^{238} U

is (Avogadro's number

= 6.023 \times 10^{23} m o l^{- 1}

)

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

4 n + 1

series is known by which name?

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

Radioactive carbon - 14, in a wood sample decays with a half-life of 5700 years. The fraction of the radioactive carbon - 14, that remains after a decay period of 17100 years is

HARD

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

The radioactive decay

_{83} {Bi}^{211} ⟶_{81} {Tl}^{207}

, takes place in

100 L

27 ° C

. Starting with

2 moles

_{83} {Bi}^{211} (t_{1 / 2} = 130 sec)

the pressure development in the vessel after

520 \sec

will be:

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

A.G.M. counter is used to study the radioactive process of first-order. In the absence of radioactive substance A, it counts 3 disintegration per second

(d p s)

. When A is placed in the

G . M

. counter, it records

23 d p s

at the start and

13 d p s

after

10 m i n u t e s

. It records

x d p s

after next

10 m i n u t e s

and A has half-life period y minutes.

x

and

y

are :

EASY

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

After the emission of an

α -

particle from the atom of

_{92} U^{238}

the number of neutrons in the atom will be

MEDIUM

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

After 20 min, the amount of certain radioactive substance disintegrating was

\frac{1}{16} th

of the original amount. What is the half-life of the radioactive substance ?

HARD

Chemistry>Physical Chemistry>Nuclear Chemistry>Theory of Radioactive Disintegration

A radioactive element

' A'

decays as follows:

\begin{matrix} A & \overset{30 min}{⟶} & B +_{2} {He}^{4} \\ B & \overset{2 days}{⟶} & C + 2 {}_{- 1}^{0}e \end{matrix}

Which of the following statements is/are incorrect?

Which of the following statements are incorrect:

Important Questions on Nuclear Chemistry

Learn and Prepare for any exam you want !