Chemistry
State the factors which affect :
(a) electron affinity
(b) electronegativity of elements in a periodic table.
Answer
(a) The Factors which affect the electron affinity are:
- Atomic size — The smaller the atomic size, the greater the electron affinity, because a small atom takes up electrons more readily than a large atom since nucleus has greater attraction on electrons.
- Nuclear charge — As the nuclear charge increases electron affinity increases because with an increase in nuclear charge the tendency of an atom to accept electrons increases.
(b) The factors affecting electronegativity are:
- Atomic size — The greater the size of the atom, the lesser the electronegativity because a small atom will pull the shared pair of electrons more than a large atom.
- Nuclear charge — As the nuclear charge increases electronegativity increases because an increase in nuclear charge increases the force of attraction on the electron.
Related Questions
Give reasons for the following:
Atomic size of an element depends on the nuclear charge of that element.
Give reasons for the following:
Down a group electronegativity should increase with increase in nuclear charge but it is seen that the electronegativity decreases.
Give reasons for the following:
If combining atoms have nearly similar electronegativities the bond between them is covalent.
Arrange the following elements as per the guidelines in brackets.
- Na, Cl, Mg, P [in decreasing order of atomic size]
- C, Li, F, N [in increasing order of electronegativity]
- Cl, Al, Na, S [in increasing order of ionization potential]
- Li, F, C, O [in increasing order of electron affinity]
- Ar, He, Ne [in increasing order of number of electron shells]