How does the metallic and non-metalic character vary on moving from left to right in a period?

Explanation

On moving from left to right in a period, the number of electrons increases by one at each succeeding element but the number of shell remains the same. Therefore, the effective nuclear charge increases and consequently the tendency of an atom to lose electron decreases and hence metallic character decreases when we move from left to right in a period. On the other hand, with increase in nuclear charge, the tendency of an atom to gain electron increases and hence non-metallic character increases. Thus, metallic character decreases and non-metallic character increases on moving from left to right in a period.