Radon undergoes decay by α -emission Rn 88 222 → t 1 / 2 = 3 . 8 d Po 84 218 + 2 4 He Which of the following statements will be true for this decay process?

60 % of the radon will decay in 5 days approximately.

MEDIUM

Earn 100

Discuss the law of radioactive disintegration.

Important Questions on Nuclear chemistry and radioactivity

EASY

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

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

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

The rate of decay per second of a radioactive sample

EASY

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

A radioactive substance

X

decays into another radioactive substance

Y

. Initially only

X

was present,

λ_{x}

and

λ_{y}

are the disintegration constants of

X

and

Y

at any time

t

. Number of nuclei

N_{y}

will be maximum when

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

A radioactive sample, at any instant, has its disintegration rate $5000 disintegration per minute$ . After

5 \min

, the rate is $1250 disintegration per minute$ . Then, the decay constant (per

\min

) is

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

{}_{27}^{60}{CO}

decays with half-life of

5.27

years to product

{}_{28}^{60}{Ni}

. What is the decay constant for such radioactive disintegration?

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

Calculate the age of the ore if

_{92} U^{238}

by successive decay changes to

_{82} {Pb}^{206}

, when a sample of uranium ore was analysed it was found that it contains 1g of U²³⁸ and 0.1 g of Pb²⁰⁶, considering that all the Pb²⁰⁶ had accumulated due to decay of U²³⁸(Half-life of U²³⁸ = 4.5 × 10⁹ yrs).

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

Activity of a radioactive sample decreases to

(\frac{1}{3})

rd of its original value in

3

days. Then, in

9

days its activity will become

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

STATEMENT-1: Specific activity of the same radioactive substance is same for 10g radioactive substance as well as 50g radioactive substance.

STATEMENT-2: Specific activity of a radioactive substance is its activity per g.

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

Radioactive disintegration rate is affected by

EASY

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

One becquerel of radioactivity is equal to

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

One of the hazards of nuclear explosion is the generation of

{}^{90}{Sr}

and its subsequent incorporation in bones. This nuclide has a half-life of

28.1 year

. Suppose one microgram was absorbed by a new-born child, how much

{}^{90}{Sr}

will remain in his bones after

20 year

MEDIUM

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

5 g

of a radioactive substance has

t_{\frac{1}{2}} = 14 h, 20 g

of the same substance will have a

t_{\frac{1}{2}}

equal to

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

It is observed that only

0.39 %

of the original radioactive sample remains undecayed after eight hours. Hence,

EASY

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

The half-life of

{At}^{215}

100 μs

. If a sample contains

215 mg

{At}^{215}

, the activity of the sample is

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

Radon undergoes decay by $α$ -emission

${}_{88}^{222}{Rn} \overset{t_{1 / 2} = 3.8 d}{\to} {}_{84}^{218}{Po} +_{2}^{4} He$

Which of the following statements will be true for this decay process?

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

Tritium,

{}_{1}^{3}H

has a half-life of

12.26 year

. A

5.00 ml

sample of tritiated water has an activity of

2.40 \times 10^{9} cpm .

How many years will it take for the activity to fall to

3.00 \times 10^{8}

cpm

HARD

Chemistry>Physical Chemistry>Nuclear chemistry and radioactivity>Radioactive decay

A small quantity of solution containing ${Na}^{24}$ radionuclide of activity $1 microcurie$ is injected into the blood of a person. A sample of the blood of volume $1 {cm}^{3}$ taken after $5 hours$ shows an activity of $296 disintegration per minute$ . Assuming that the radioactive solution mixes uniformly in the blood of the person, what will be the total volume of blood in the body of the person?