Answer:
It is the tendency of an atom to attract the electron towards itself.
Explanation:
Definition:
It is the tendency of an atom to attract the electron towards itself.
Explanation:
Atoms with large electronegativity difference when bonded they form ionic compound.
For example:
Sodium chloride is ionic compound. The electronegativity of chlorine is 3.16 and for sodium is 0.93. There is large difference is present. That's why electron from sodium is transfer to the chlorine. Sodium becomes positive and chlorine becomes negative ion. Both atoms are bonded together electrostatic attraction occur between anion and cations.
When there is smaller elctronegativity difference is present between bonded atoms they form covalent bond because any one atom don't have a high tendency to completely gain the electron.
For example:
In water the electronegativity of oxygen is 3.44 and hydrogen is 2.2. That's why electron pair attracted more towards oxygen, thus oxygen becomes partial negative and hydrogen becomes partial positive
.
Electronegativity trend along period:
As we move from left to right across the periodic table the number of valance electrons in an atom increase. The atomic size tend to decrease in
same period of periodic table because the electrons are added with in the same shell. When the electron are added, at the same time protons are also added in the nucleus. The positive charge is going to increase and this charge is greater in effect than the charge of electrons. This effect lead to the greater nuclear attraction and electronegativity increase from left to right in period.
Electronegativity trend along group:
As we move down the group atomic radii increased with increase of atomic number. The addition of electron in next level cause the atomic radii to increased. The hold of nucleus on valance shell become weaker because of shielding of electrons thus size of atom increased and electronegativity decrease.
