A smoke detector is a device that detects smoke, typically as an indicator of fire. In this device, we see one of the civilian applications of nuclear chemistry. An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters. Several technological advances were introduced into icebreaking technology over the years, but it was not until the introduction of nuclear power in the Soviet icebreaker Lenin in 1959 that icebreakers developed to their full potential.

Technetium-99m is a meta-stable nuclear isomer of technetium-99, symbolised as 99mTc, and is used in tens of millions of medical diagnostic procedures annually, making it the most commonly used medical radioisotope.

The Radura is the international symbol indicating that a food product has been irradiated. The Radura is usually green and resembles a plant in circle. Food irradiation is a process of treating a food to a specific dosage of ionizing radiation for a predefined length of time. This process slows or halts spoilage due to the growth of pathogens. Further applications include sprout inhibition, delay of ripening, increase of juice yield, and improvement of rehydration.

In 1896, Henri Becquerel was investigating phosphorescence in uranium salts when he discovered a new phenomenon which came to be called radioactivity. He, Pierre Curie and Marie Curie began investigating the phenomenon. In the process, they isolated the element radium, which is highly radioactive.

Nuclear fission is the process of splitting a nucleus into roughly equal parts, and releasing energy and neutrons in the process. If these neutrons are captured by another unstable nucleus, they can fission as well, leading to a chain reaction. The average number of neutrons released per nucleus that go on to fission another nucleus is referred to as k. Values of k larger than 1 mean that the fission reaction is releasing more neutrons than it absorbs, and therefore is referred to as a self-sustaining chain reaction.

Magnetic confinement uses magnetic and electric fields to heat and squeeze the hydrogen plasma.Microwaves, electricity and neutral particle beams from accelerators heat a stream of hydrogen gas. This heating turns the gas into plasma. This plasma gets squeezed by super-conducting magnets, thereby allowing fusion to occur. The most efficient shape for the magnetically confined plasma is a donut shape (toroid). A reactor of this shape is called a tokamak.The ITER project in France is using this method.

Raja Ramanna was an Indian nuclear scientist and a prominent physicist, is best known for his leadership directing the research integral for the development of Indian nuclear programme in its early stages. Having started and joined the nuclear programme in 1964, Ramanna worked under Homi Jehangir Bhabha, and later, after the disastrous death of Homi Bhaba, Ramanna was immediately elevated to become the directing officer of this programme.

The process nuclear fusion may release or absorb energy. When the resulting nucleus is lighter than that of iron, energy is normally released; when the resulting nucleus is heavier than that of iron, energy is generally absorbed.

CIRUS stands for Canada-India Reactor, U. S. CIRUS was supplied by Canada in 1954, but uses heavy water (deuterium) supplied by the United States. It is the second oldest reactor in India. Even if the reactor has a life of twenty more years, India had declared that this reactor would be shut down by 2010 in accordance with the Indo-US nuclear accord reached between Indian Prime Minister Manmohan Singh and US President George W. Bush. The reactor was shut down on 31 December 2010.

Cold fusion is a hypothetical type of nuclear reaction that would occur at, or near, room temperature, compared with temperatures in the millions of degrees that is required for "hot" fusion. Cold fusion gained attention after reports in 1989 by Stanley Pons and Martin Fleischmann, then one of the world's leading electrochemists.

Pokhran-II refers to peaceful test explosions of five nuclear devices, three on 11 May and two on 13 May 1998, conducted by India at the Pokhran test range. These nuclear tests resulted in a variety of sanctions against India by a number of major states. On 18 May 1974, India exploded its first nuclear device in an operation code named Smiling Buddha (Pokhran-I). After about a quarter century, on 11 May 1998, Operation Shakti (Pokhran-II) was carried out; Shakti was the codename for the nuclear devices that were detonated.

Institute for Plasma Research (IPR) is an autonomous physics research institute located in India. The institute is involved in research in aspects of plasma science including basic plasma physics, research on magnetically confined hot plasmas and plasma technologies for industrial applications. It is a large and leading plasma physics organization in India. The institute is mainly funded by Department of Atomic Energy. IPR is playing major scientific and technical role in Indian partnership in the international fusion energy initiative ITER.

The Dhruva reactor is India's largest nuclear research reactor. Located in the Mumbai (Bombay) suburb of Trombay at the Bhabha Atomic Research Centre (BARC), it is India's primary generator of weapons-grade plutonium-bearing spent fuel for its nuclear weapons program. Originally named the R-5, this pool-type reactor first went critical on 8 August 1985 after 10 years of construction.

The Raja Ramanna Centre for Advanced Technology is a unit of Department of Atomic Energy, Government of India, engaged in R&D in non-nuclear front-line research areas of Lasers, Particle Accelerators and related technologies.

Correct answer is (4).