Which of the following will be a better shield against š¯›¾-rays?
Correct answer: C. Lead
- A. Ordinary water
- B. Heavy water
- C. Lead
- D. Aluminum
Explanation
Gamma rays are known to have maximum penetration they can penetrate several metals. The best shielding against them is elements with high atomic numbers and high density, such as lead. The atomic number of Lead is 82.Gamma rays travel at the speed of light, and they can travel thousands of meters in the air before spending their energy. They can be shielded by water but a huge amount would be required: 13.8 feet of water, about 6.6 feet of concrete, or about 1.3 feet of Lead is required to shield against gamma rays. Aluminium is less dense and gamma rays can penetrate through them completely.
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About Dawn of Modern Physics
Classical physics cannot explain blackbody radiation and related observations, leading to Planckā€™s quantum theory, in which energy is emitted or absorbed in discrete packets. Photons provide the particle model of light, with energy and momentum linked to frequency and wavelength, including the photoelectric effect and its threshold frequency.
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