Which among the following elements is used in nuclear reactors as moderator?
Which among the following elements is used in nuclear reactors as moderator?
- Ca
- K
- Mg
- Be
The Correct Option is D
Solution and Explanation
Beryllium has excellent neutron moderating properties due to its low neutron absorption cross-section and high scattering efficiency. It is capable of slowing down the neutrons effectively without significantly absorbing them. Therefore, beryllium is a commonly used material in certain types of nuclear reactors as a moderator to control the speed of neutrons.
Therefore the element used in nuclear reactors as a moderator is option (D) beryllium (Be).
Top Questions on Hydrogen
Consider the following data:
- Heat of formation of \( CO_2(g) \) = -393.5 kJ mol\(^{-1}\)
- Heat of formation of \( H_2O(l) \) = -286.0 kJ mol\(^{-1}\)
- Heat of combustion of benzene = -3267.0 kJ mol\(^{-1}\)
The heat of formation of benzene is ……… kJ mol\(^{-1}\) (Nearest integer).Which of the following is/are correct with respect to the energy of atomic orbitals of a hydrogen atom?
(A) \( 1s<2s<2p<3d<4s \)
(B) \( 1s<2s = 2p<3s = 3p \)
(C) \( 1s<2s<2p<3s<3p \)
(D) \( 1s<2s<4s<3d \)
Choose the correct answer from the options given below:An ideal gas undergoes a cyclic transformation starting from point A and coming back to the same point by tracing the path A→B→C→D→A as shown in the three cases below.
Choose the correct option regarding \(\Delta U\):- The ratio of magnitude of potential energy and kinetic energy for \(5^{th}\) excited state of hydrogen atom is
- If wavelength of the first line of the Paschen series of hydrogen atom is _____ nm, then the wavelength of the second line of this series is nm (Nearest integer)
Concepts Used:
Heavy Water
Heavy water (2H2O, D2O - deuterium oxide) is a form of water that consists only of deuterium rather than the common hydrogen-1 isotope that composes most of the hydrogen in normal water. The presence of the heavier hydrogen isotope gives the water distinct nuclear properties, and the increase of mass gives it slightly distinct physical and chemical properties when compared to normal water.
There are some other heavy forms of water such as;
- Semiheavy water
- Heavy-oxygen water
- Tritiated water
Properties of Hard Water:
- Heavy water is slighter dissociated than light water at a given temperature, and the true concentration of D+ ions is slighter than H+ ions would be for a light water sample at the same temperature.
- Heavy water is more concentrated than ordinary water, and heavy water has physically distinct properties that can be seen without equipment if a frozen sample is dropped into normal water, as it will sink.