Advertisements
Advertisements
प्रश्न
State how electrons are distributed in an atom. Explain in brief the rules which govern their distribution.
Advertisements
उत्तर
(a) Electrons revolve around the nucleus in imaginary paths called shells or orbits. Shells start from the nucleus to outwards.
Rules: The maximum number of electrons in a shell is given by 2n2. Where n is the number of shell i.e. 1st shell can have a maximum of 2 electrons.
2n2 = 2(1)2 = 2 × 1 = 2
2nd shell can have maximum of 8 electrons
2n2 = 2(2)2 = 2 × 4 = 8
3rd shell can have maximum of 18 electrons
2n2 = 2 (3)2 = 2 × 9 = 18 and so on….
(b) Outer most orbit cannot have more than 8 electrons and 18 in penultimate orbit.
(c) A new shell cannot start until previous is filled completely.
APPEARS IN
संबंधित प्रश्न
FILL IN THE BLANK
The electrons revolving in shells close to the nucleus are called ................... electrons.
WRITE SHORT ANSWER
What is an atom?
WRITE SHORT ANSWER
Name the isotopes of hydrogen.
Draw the electronic configuration of the following elements clearly stating the number of neutrons and protons in their nucleus.
a. Beryllium b. Silicon
c. Chlorine d. Aluminium
e. Nitrogen
Compare a proton and a neutron in respect of mass and charge.
The particle not present in an ordinary hydrogen atom is :
Name the three fundamental particles of an atom.
Define the term Nucleons.
Explain how the modern atomic theory contradicted Dalton’s atomic theory.
Select the correct answer from the choice in the bracket to complete the sentence:
An element ‘X’ has six electrons in its outer or valence shell. Its valency is __________.
