Question

define valency. how does it vary along a peroid
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Answer 1

Answer:

the number of electrons that must be lost or gained by an atom to obtain a stable electron configuration. In the periodic table period, the valency of an element first increases and then decreases. ... The valency varies from +1 to +4 or -4 through these 8 elements, in the first 4 elements of these 8 elements.

Answer 2

Answer:

the no. of electron in the outer most shell of the element is called valency of an element