Explain with examples:
(i) Atomic number
(ii) Mass number,
(iii) Isotopes and
(iv) Isobars.
Give any two uses of isotopes.
(i) Atomic number: The atomic number of an element is equal to the number of protons in the nucleus of its atom. e.g., Oxygen has 6 protons hence atomic no. = 6.
(ii) Mass number: The mass number of an atom is equal to the number of protons and neutrons in its nucleus.
Nucleons = number of protons + number of neutrons
Example: Protons + Neutrons = Nucleus
= Mass number, 6 + 6 = 12.
(iii) Isotopes: Isotopes are atoms of the same element which have different mass numbers but the same atomic numbers
E.g., 11H, 21H,31H.
(iv) Isobars: Isobars are atoms having the same mass number but different atomic numbers.
E.g., 4020Ca, 4018Ar.
Both calcium and argon have the same mass number but a different atomic number.
Two uses of isotopes are:
(i) An isotope of iodine is used in the treatment of goiter.
(ii) An isotope of uranium is used as a fuel in nuclear reactors.
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