
Chlorine is an element of atomic number . It is a mixture of isotopes having mass numbers of and .
What is meant by the term atomic number?

Important Questions on Atomic Structure
Chlorine is an element of atomic number . It is a mixture of isotopes having mass numbers of and .
Write down the electronic configuration of the chlorine atom.

Chlorine is an element of atomic number . It is a mixture of isotopes having mass numbers of and .
Complete the given table:
Element | Number of electrons | Number of protons | Number of neutrons |
___ | ___ | ___ | |
___ | ___ | ___ |

Five atoms are labelled A to E.
Atoms | Mass number | Atomic number |
A | ||
B | ||
C | ||
D | ||
E |
(a) Which of these above mentioned atoms,
(i) contains protons?
(ii) has an electronic configuration ?
(b) Write down the formula of the compound formed by atoms and .




Elements and have atomic numbers , and respectively.
State which one is (i) a non-metal; (ii) a metal and (iii) chemically inert.

