Define the following terms (1)Atom (2) Isotope (3) Atomic number (4) Atomic mass (5) Moderator in nuclear reactor.

Question

(1)Atom

(2) Isotope 

(3) Atomic number 

(4) Atomic mass 

(5) Moderator in nuclear reactor

Answer 1

• Atom: The basic unit of matter, consisting of a nucleus made up of protons and neutrons, surrounded by electrons in orbitals. Atoms are the building blocks of all substances.

• Isotope: Variants of a particular chemical element that have the same number of protons but different numbers of neutrons, resulting in different atomic masses. For example, carbon-12 and carbon-14 are isotopes of carbon.

• Atomic Number: The number of protons in the nucleus of an atom, which determines the element's identity and its position in the periodic table. It is usually denoted by the symbol ZZZ.

• Atomic Mass: The weighted average mass of an atom of an element, measured in atomic mass units (amu), taking into account the relative abundances of its isotopes. It reflects the total number of protons and neutrons in the nucleus.

• Moderator in a Nuclear Reactor: A substance used to slow down fast neutrons produced during fission reactions, increasing the likelihood of further fission. Common moderators include water, heavy water, and graphite. Slower neutrons are more effective at sustaining the nuclear chain reaction.