Content text Chemistry-XI-Atomic structure-atomic number and mass number.pptx
ATOMIC STRUCTURE
ATOMIC NUMBER & MASS NUMBER
Atomic number The number of protons (positively charged particles ) inside the nucleus is called atomic number. Atomic number is denoted by ‘Z’ Atom, on the whole, is electrically neutral i.e., the number of negatively charged particles (electrons) outside the nucleus is equal to the number of positively charged particles inside the nucleus.
Mass number is the sum of the number of protons and number of neutrons inside the nucleus. It is denoted by ‘A’ Mass number is a whole number. A= Z + n ; n=A-Z Mass Number ‘n’ is the number of neutrons.