TNPSC Chemistry - Radioactivity
Exam Duration: 45 Mins Total Questions : 30
Consider the following statements with reference to X-rays
1. They produce heat when absorbed by matter.
2. They are generated when fast moving electrons strike a metal target.
3. They can penetrate through a thin sheet of aluminum.
Which of the statements given above are correct?
- (a)
1,2 and 3
- (b)
1 and 2
- (c)
2 and 3
- (d)
1 and 3
Consider the following statements:
In a nuclear reactor, self-sustained chain reaction is possible, because
1. More neutrons are released in each of the fission reactions.
2. The neutrons immediately take part in the fission process.
3. The fast neutrons are slowed down by graphite.
4. Every neutron released in the fission reaction initiates further fission.
Which of the statements given above are correct?
- (a)
1,2 and 3
- (b)
1 and 3
- (c)
2 and 4
- (d)
2, 3 and 4
Which one of the following has the highest frequency?
- (a)
Cosmic rays
- (b)
X-rays
- (c)
Radio waves
- (d)
Microwaves
Consider the following substances:
1. Heavy Water
2. Graphite
Which of the substances given above are used as a moderator in a nuclear reactor?
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
Neither 1 nor 2
In an atomic explosion, enormous energy is released which is due to the
- (a)
Conversion of neutrons into protons
- (b)
Conversion of chemical energy into heat energy
- (c)
Conversion of chemical energy into nuclear energy.
- (d)
Conversion of mass into energy.
What is the correct ascending order for frequencies of the following radiations?
1. Visible
2. X-rays
3. Ultraviolet
4. Radio waves
- (a)
1,3,2,4
- (b)
3,2,4,1
- (c)
4,1,3,2
- (d)
4,3,1,2
In spontaneous beta particle emission, what is the source of emitted electron?
- (a)
The nucleus
- (b)
The 1s-orbital
- (c)
The outermost occupied orbital
- (d)
A random orbital.
Consider the following statements:
1. X-rays can pass through aluminum.
2. X-rays can be deflected by a magnetic field.
3. X-rays move with a velocity less than the velocity of ultraviolet rays in the vacuum.
Which of the statements given above are correct?
- (a)
1,2 and 3
- (b)
Only 1
- (c)
2 and 3
- (d)
1 and 2
Which one of the following is not radioactive?
- (a)
Astatine
- (b)
Francium
- (c)
Tritium
- (d)
Zirconium
Assertion (A): X-rays are used for studying the structure of crystals.
Reason (R): The difference between the atoms of crystals is of the order of wavelength of X-rays
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true but R is not the correct explanation of A
- (c)
A is true, but R is False
- (d)
A is false, but R is true
Radio Carbon dating is used to estimate the age of
- (a)
rocks
- (b)
old monuments
- (c)
fossils
- (d)
living trees
In which categories did Marie Curie win her two different Nobel Prizes?
- (a)
Physics and Chemistry
- (b)
Chemistry and Medicine
- (c)
Physics and Medicine
- (d)
Chemistry and Peace.
Which one of the following elements is essential for construction of nuclear reactors?
- (a)
Cobalt
- (b)
Nickel
- (c)
Zirconium
- (d)
Tungsten
Radioactivity is a natural disintegration of nuclei of heavy elements because only heavy elements
- (a)
Contain alpha particles
- (b)
Can have unstable nuclei with neutron-proton ratio being quite uneven
- (c)
contain excess of neutrons
- (d)
can produce lead as the end product
Which one among the following is the mean life of radioactive elements?
- (a)
Equal to half-life
- (b)
Less than half-life
- (c)
0.693t1/2
- (d)
1.44 t1/2
Choose the incorrect statement.
- (a)
P32 is used in the treatment of Leukemia.
- (b)
I131 is used in the treatment of thyroid gland.
- (c)
Co60 can't be used for cancer treatment.
- (d)
Excessive use of radioactive elements is responsible for cancerous growth.
The ratio of velocity of X-rays to that of gamma rays is
- (a)
<1
- (b)
>1
- (c)
1
- (d)
depends upon the ratio of their frequencies.
A radioactive decay process has a half-life of 4 years. The amount of the reactant remaining after 12 years is
- (a)
10%
- (b)
12.5%
- (c)
25%
- (d)
87.5%
Which one of the following reactions is the main cause of the energy radiation from the sun?
- (a)
Fusion reaction
- (b)
Fission reaction
- (c)
Chemical reaction
- (d)
Diffusion reaction
Which one of the following is not electromagnetic in nature?
- (a)
Cathode-rays
- (b)
X-rays
- (c)
Gamma-rays
- (d)
Infrared-rays
Consider the following statements:
1. Radioactivity tracers are commonly used in the medical field and also in the study of plants and animals.
2. Radiation is used and produced in nuclear reactors, which controls fission reactions to produce energy and new substances from the fission products.
3. Radiation is also used to sterilize medical instrument and food.
Which of the statements given above are correct?
- (a)
1 and 2
- (b)
1 and 3
- (c)
2 and 3
- (d)
1, 2 and 3
Assertion (A): All compounds contain more than one element.
Reason (R): All compounds are heterogeneous mixtures.
- (a)
Both A and R are true and R is the correct explanation of A
- (b)
Both A and R are true but R is not the correct explanation of A
- (c)
A is true, but R is False
- (d)
A is false, but R is true.
Consider the following statements:
1. Carbon-14 dating can determine the age of an artifact, that is up to 40000 years old.
2. After burning a small piece of an artifact, scientists compare the amount of Carbon-14 to the amount of Carbon-12 to determine the age of the object.
Which of the statements given above are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
1 and 2
- (d)
None of the above
The function of heavy water in a nuclear reactor is to
- (a)
slow down the speed of neutrons
- (b)
increase the speed of neutrons
- (c)
cool down the reactor
- (d)
stop the nuclear reaction
The gas which turns limewater milky is
- (a)
Carbon Dioxide
- (b)
Carbon Monoxide
- (c)
Ammonia
- (d)
Nitrogen Dioxide
Which electromagnetic radiation emitted by radioactive substances?
- (a)
Gamma-rays
- (b)
Radio waves
- (c)
Microwaves
- (d)
X-rays
Assertion (A): Alpha Particles and Beta Particles can be detected by a Geiger counter.
Reason (R): Neutron can be detected by conversion into the Alpha particle by the addition of 510 B.
- (a)
Both A and R are individually true and R is the correct explanation of A
- (b)
Both A and R are individually true but R is not the correct explanation of A
- (c)
A is true, but R is False
- (d)
A is false, but R is true.
Consider the following statements: Loss of Beta particle is equivalent to
1. Increase in one proton only.
2. A decrease in one neutron only.
Which of the statements given above are correct?
- (a)
Only 1
- (b)
Only 2
- (c)
Both 1 and 2
- (d)
Neither 1 nor 2
Which one of the following is correct about Gamma-rays?
- (a)
They are emitted before Alpha and Bita-rays.
- (b)
They are emitted after Alpha and Bita-rays.
- (c)
They are emitted simultaneously with Alpha and Beta-rays.
- (d)
They are emitted either along with Alpha-rays or along with Beta-rays.
Match the column I and Column II and select the correct answer using the code given below:
Column I ( Nuclear reactor components) | Column II (Substance used) |
A. Moderator | 1. Sodium |
B. Control rods | 2. Uranium |
C. Fuel rods | 3. Graphite |
D. Coolant | 4. Boron |
- (a)
A B C D 3 4 2 1 - (b)
A B C D 1 2 4 3 - (c)
A B C D 3 1 2 4 - (d)
A B C D 2 4 1 3