Know Nuclear


Every piece of matter in the Universe, as far as we know, is made up of one or more elements from the Periodic Table. The smallest part of an element that can exist is an atom.

Nuclear Basicsmass_number

Atoms are made up of  protons and neutrons, collectively called nucleons, surrounded by electrons.

Things you need to know:

The symbol $_Z^A {\rm{X}}$is used for the nucleus of an element that has the chemical symbol X, a mass number A, and atomic number Z.


The symbol $_Z^A {\rm{X}}$ is used for a particular isotope. If A = 14 and Z = 6,

  • How many protons does the isotope have in its nucleus?
  • How many neutrons does the isotope have in its nucleus?
  • What is the element X?
  • The atomic number Z = 6 so the isotope has 6 protons in its nucleus.
  • The number of neutrons in the nucleus of the isotope is A-Z = 14-6 = 8.
  • The element that has an atomic number 6 is carbon.

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