Question

Electropositive of element: * Down a group * Across the period. Justify with reasons.

Answer 1

Electropositivity of an element is the property of an element to donate electrons from its outer most orbital.

- It increases down the group.
As we go down the group, number of orbitals in the elements increases. So the distance between the nucleus and the outermost electron increases and hence the force of attraction between them decreases. Also the force of attraction is shielded by other electrons. So the electron can easily go out of the orbital.
- It decreases across the period.
As we go across a period, no. of electrons in the outer orbital increases. Thus the force of attraction also increases and the it becomes more difficult for the electron to escape from the orbital. hence electropositivity decreases across the period.