Things around us are made up of ____
In 1803, ___ considered that elements consist of atoms
____ discovered cathode rays, known as electrons
_____ discovered positive rays
Positive rays were named as protons by___
In 1932, James Chadwick discovered the chargeless particles called____
In 1911, the British scientist, Ernest Rutherfordexplained that the mass of an atom is concentrated in its central part called ____
____ and her husband ____detected radioactivity in ‘Pitchblende’, a tiny black substance.
The elements whose atomic number is more than ___ undergo spontaneous radioactivity. Eg: uranium, radium, etc.
There are only two elements, which have been identified as radioactive substances with atomic number less than 82. They are ____
Technetium (Tc) atomic number is___
Promethium (Pm) atomic number is___
There have been ___ radioactive substances discovered so far.
The phenomenon by which even light elements are made radioactive, by artificial or induced methods, is called____
____ is exhibited by elements with atomic number more than 83.
___& is exhibited by elements with atomic number less than 83.
The SI unit of radioactivity is
____, named after the planet Uranus, was discovered by Martin Klaproth
A nuclear reaction in which an unstable parent nucleus emits an alpha particle and forms a stable daughter nucleus, is called____.
A nuclear reaction, in which an unstable parent nucleus emits a beta particle and forms a stable daughter nucleus, is called____
The process of breaking (splitting) up of a heavier nucleus into two smaller nuclei with the release of a large amount of energy and a few neutrons is called___
The average energy released in each fission process is about____
A fissionable material is a radioactive element, which undergoes fission in a sustained manner when it absorbs a neutron.
It is also termed as____
All isotopes of uranium do not undergo nuclear fission when they absorb a____
There are some radioactive elements, which can be converted into fissionable material. They are called as_____
A ____ is a self�propagating process in which the number of neutrons goes on multiplying rapidly almost in a geometrical progression
In the ____ chain reaction the number of neutrons released is maintained to be one
The minimum mass of a fissile material necessary to sustain the chain reaction is called ______
If the mass of the fissile material is less than the critical mass, it is termed as___
If the mass of the fissile material is more than the critical mass, it is termed as___
The atom bomb is based on the principle of ___ chain reaction.
_____ is the unit used in nuclear physics to measure the energy of small particles.
The energy released in a nuclear fission process is about ____
The process in which two lighter nuclei combine to form a heavier nucleus is termed ___as ___
The relation between mass and energy proposed by Einstein is ____
The nuclear bomb that was dropped in Hiroshima during World War II was called as ___
The bomb, which was subsequently dropped over Nagasaki was called as____
The stars like our Sun emit a large amount of energy in the form of light and heat. This energy is termed as the____
Hydrogen bomb is based on the principle of _____
The energy released in a hydrogen bomb (or fusion bomb) is much higher than that released in an ____
The radio isotope of ____helps to increase the productivity of crops.
____ are used as tracers to diagnose the nature of circulatory disorders of blood, defects of bone metabolism, to locate tumors, etc
____ (Na24) is used for the effective functioning of heart.
____ is used to cure goiter.
______ is used to diagnose anaemia and also to provide treatment for the same.
____ is used in the treatment of skin diseases.
Radio cobalt (Co60) and radio-gold (Au198) are used in the treatment of___ skin
____ are used to sterilize the surgical devices as they can kill the germs and microbes.
In industries, ___are used as tracers to detect any manufacturing defects such as cracks and leaks.
An isotope of ____is used in the airlines to detect the explosives in the luggage.
An isotope of ____ is used in many industries as a smoke detector.
Using the technique of ____, the age of the Earth, fossils, old paintings and monuments can be determined.
Safe limit of overall exposure to radiation is given as ___ milli sievert per year
____ is a device used to detect the levels of exposure to an ionizing radiation.
A ____’ is a device in which the nuclear fission reaction takes place in a self-sustained and controlled manner to produce electricity
The first nuclear reactor was built in 1942 at ___
A ___” is used to slow down the high energy neutrons to provide slow neutrons
____ and heavy water are the commonly used moderators
___ are used to control the number of neutrons in order to have sustained chain reaction.
A ____ is used to remove the heat produced in the reactor core, to produce steam.
____ are widely used in power generation
Nuclear power is the ___ largest source of power in India.
___ Atomic Power Station is India’s first nuclear power station.