Question

how would the metallic character vary in groups and periods

Answer 1

in periods the metallic character decreases but in groups the metallic character increases

Answer 2

Metallic character decreases as you move across a period in the periodic table from left to right. This occurs as atoms more readily accept electrons to fill a valence shell than lose them to remove the unfilled shell. Metallic character increases as you move down an element group in the periodic table.