Tag: nuclear physics

Questions Related to nuclear physics

The specific activity (per gm) of radium is nearly-

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. 1 Bq

  2. 11 Ci

  3. $ 3.7 \times 10^{10} Bq$

  4. 1 m Ci

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Correct Option: C

The radioactivity of an old sample of a liquid due to tritium (half life $12.5$ years) was found to be only about $3$% of that measured in a recently purchased bottle marked $7$ year old. The sample must have been prepared about:

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. $70$ year

  2. $63.24$ year

  3. $420$ year

  4. $300$ year

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Correct Option: B
Explanation:

$\begin{array}{l} Hence, \ \frac { N }{ { { N _{ 0 } } } } =0.03=\left( { -\lambda t } \right)  \ In\left( { 0.03 } \right) =-\lambda t=\frac { { -In\left( 2 \right) \times t } }{ { \frac { { { T _{ 1 } } } }{ 2 }  } }  \ t=\frac { { In\left( { 0.03 } \right) \times \frac { { { T _{ 1 } } } }{ 2 }  } }{ { -In\left( 2 \right)  } } =63.24\, years \end{array}$

Hence,
option $(B)$ is correct answer.

Radioactive nuclei injected into a patient collect at certain sites within the body,undergo radioactive decay and emit electromagnetic radiation.These radiations can then be recorded by a detector.This procedure provides an important diagnostic toll called

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. Gamma camera

  2. CAT scan

  3. Radio tracer technique

  4. Gamma ray spectroscopy

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Correct Option: C
Explanation:

Tracers are a common application of radioisotopes. A tracer is a radioactive element whose pathway through which a chemical reaction can be followed. Tracers are commonly used in the medical field and in the study of plants and animals. Radioactive Iodine-131 can be used to study the function of the thyroid gland assisting in detecting disease.

Fill in the blanks :

The mass of a body remains constant till the velocity of body is ............

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. much less than the velocity of light

  2. equal to velocity of light

  3. much higher than the velocity of light

  4. none of the above

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Correct Option: A
Explanation:

According to Einstein if a body moves almost more than the velocity of light then it starts losing its mass.He gave this concept by a formula that is $E=m c^{2}$.Hence for the body to maintain constant mass it has to move with the speed less than the velocity of light.

The atomic number of natural radioactive element is .....................

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. greater than 82

  2. less than 82

  3. not defined

  4. atleast 92

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Correct Option: A
Explanation:

A

All elements with atomic numbers greater than 83 are radio isotope meaning that these elements have unstable nuclei and are radioactive. 

Which of the following can be diagnosed by Iodine-131 radioisotope?

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. Kidneys

  2. Heart

  3. Lungs

  4. Thyroid

  5. Bone marrow

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Correct Option: D
Explanation:

Iodine in food is absorbed by the body and preferentially concentrated in the thyroid where it is needed for the functioning of that gland. Thus the health problem related to thyroid can be diagnosed by Iodine−131 radioisotope. 

The electromagnetic radiation observed in Radioactivity is ..............

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. $\alpha$ - particle

  2. $\beta$ - particle

  3. $\gamma$ - rays

  4. X - rays

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Correct Option: C
Explanation:

Gamma ray (also called gamma radiation) is penetrating electromagnetic radiation of a kind arising from the radioactive decay of atomic nuclei. It consists of photons in the highest observed range of photon energy.

Alpha particles have________kinetic energy and momentum with them. Fill in the blank. 

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. less

  2. large

  3. no

  4. all of the above

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Correct Option: B
Explanation:

Alpha particles have large kinetic energy and momentum with them. They are used to bombard the atomic nuclei to convert one element into another (for transmutation)

Nearly all isotopes of elements having mass number _______ are radioactive. 
chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. Lower than 82

  2. Higher than 82

  3. Higher than 69

  4. Lower than 69

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Correct Option: B
Explanation:

The isotopes of nearly all the elements of atomic number higher than 82 (i.e. lead) are radioactive. There are called the natural radioactive substances.

Which of the following is a radioactive substance?

chemistry nuclear physics types of radioactivity nuclear chemistry and radioactivity radioactivity

  1. Uranium

  2. Radium

  3. Thorium

  4. All of the above 

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Correct Option: D
Explanation:

Substances which disintegrate (or decay) by the spontaneous emission of radiations are called the radioactive substances. Eq. Uranium, radium, polonium, thorium, actinium etc.