Is it possible for a hydrogen ( H 1 1 ) nucleus to emit an alpha particle? Give a reason for your answer.

No, as alpha radiation is nothing but the nucleus of helium ( H 2 4 e ). With the emission of an alpha particle ( H 2 4 e ), the atomic number of the radioactive nucleus decreases by two and mass number by four. The nucleus of hydrogen does not contain two protons and two neutrons, and it has less number of electrons than the alpha particle. So it can not emit an alpha particle.

MEDIUM

Earn 100

The radiation from a naturally occurring radioactive substance, as seen after deflection by a magnet in one direction, are:

50% studentsanswered this correctly

Important Questions on Nuclear Energy

EASY

Science>Physics>Nuclear Energy>Radioactivity

A radioactive element has a rate of disintegration

10, 000

disintegrations per minute at a particular instant. After four minutes it becomes

2500

disintegrations per minute. The decay constant per minute is

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

In a radioactive decay chain, the initial nucleus is

_{90}^{232} Th

. At the end, there are

6

α

-particles and

4 β

-particles which are emitted. If the end nucleus is

_{Z}^{A} X, A

and

Z

are given by:

EASY

Science>Physics>Nuclear Energy>Radioactivity

The half-life of a radioactive substance is

30 \min

. The time (in minutes) taken between

40 %

decay and

85 %

decay of the same radioactive substance is

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

A piece of wood from a recently cut tree shows

20

decays per minute. A wooden piece of the same size placed in a museum (obtained from a tree cut many years back) shows

2

decays per minute. If the half-life of

C^{14}

5730 years

, then the age of the wooden piece placed in the museum is approximately
[This question was awarded a bonus and proper correction was made to avoid that]

EASY

Science>Physics>Nuclear Energy>Radioactivity

Which of the following is the high-frequency radiation produced in nuclear reactions and also emitted by radioactive nuclei that are used in medicine to destroy cancer cells?

EASY

Science>Physics>Nuclear Energy>Radioactivity

Radioactive material

A

has decay constant

8 λ

and material

B

has decay constant

λ

. Initially they have the same number of nuclei. After what time, the ratio of number of nuclei of material

A

to that

B

will be

\frac{1}{e} ?

HARD

Science>Physics>Nuclear Energy>Radioactivity

Let

N_{β}

be the number of

β

particle emitted by

1 gram

{Na}^{24}

radioactive nuclei having a half life of

15 h

. In

7.5 h

, the number

N_{β}

is close to

[N_{A} = 6 .023 \times 10^{23} {mole}^{- 1}]

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

A radio isotope ‘

X

’ with a half life

1.4 \times 10^{9}

years decays to ‘

Y

’ which is stable. A sample of the rock from a cave was found to contain ‘

X

’ and ‘

Y

’ in the ratio

1 : 7

. The age of the rock is

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

The mass number of an element is NOT changed when it emits

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

Which one of the following statements is true with regard to a greenhouse?

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

Half-lives of two radioactive elements

A

and

B

are

20 minutes

and

40 minutes

, respectively. Initially, the samples have an equal number of nuclei. After

80 minutes

, the ratio of decayed numbers of

A

and

B

nuclei will be:

EASY

Science>Physics>Nuclear Energy>Radioactivity

The difference between Isotopes of an element is due to the presence of which different numbers?

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

Two radioactive substances

A

and

B

have decay constants

5 λ

and

λ

respectively. At

t = 0

, a sample has the same number of the two nuclei. The time taken for the ratio of the number of nuclei to become

{(\frac{1}{e})}^{2}

will be

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

The half-life of a particle of mass

1.6 \times 10^{- 26} kg

6.9 s

and a stream of such particles is travelling with the

K . E .

of a particle being

0.05 eV

. The fraction of particles which will decay when they travel a distance of

1 m

is,

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

Two radioactive materials

A

and

B

have decay constants

10 λ

and

λ

, respectively. If initially they have the same number of nuclei, then the ratio of the number of nuclei of

A

to that of

B

will be

\frac{1}{e}

after a time:

EASY

Science>Physics>Nuclear Energy>Radioactivity

Is it possible for a hydrogen (

{}_{1}^{1}H

) nucleus to emit an alpha particle? Give a reason for your answer.

HARD

Science>Physics>Nuclear Energy>Radioactivity

In a radioactive sample,

_{19}^{40} K

nuclei either decay into stable

_{20}^{40} C a

nuclei with decay constant

4.5 \times 10^{- 10}

per year or into stable

_{18}^{40} A r

nuclei with decay constant

0.5 \times 10^{- 10}

per year. Given that in this sample all the stable

_{20}^{40} C a

and

_{18}^{40} A r

nuclei are produced by the

_{19}^{40} K

nuclei only. In time

t \times 10^{9}

years, if the ratio of the sum of stable

_{20}^{40} C a

and

_{18}^{40} A r

nuclei to the radioactive

_{19}^{40} K

nuclei is

99,

the value of t will be : [Given

l n 10 = 2.3

]

MEDIUM

Science>Physics>Nuclear Energy>Radioactivity

Using a nuclear counter the count rate of emitted particles from a radioactive source is measured. At

t = 0

it was

1600

counts per second and

t = 8

seconds it was

100

counts per second. The count rate observed, as counts per second, at

t = 6

seconds is close to:

EASY

Science>Physics>Nuclear Energy>Radioactivity

How many types of isotopes does Scandium have?

EASY

Science>Physics>Nuclear Energy>Radioactivity

Isotopes differ in _____.

The radiation from a naturally occurring radioactive substance, as seen after deflection by a magnet in one direction, are:

Important Questions on Nuclear Energy

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