What are the trends in the valency of the periodic table?

Answer 1

The trend for the valence electron(s) is mostly significant to the the elements in s and p blocks. In other words groups 1-2 and 13-18 in the modern periodic table. The first four aforementioned groups have 1, 2, 3 and 4 electrons which can be shared with an other atom. The elements in groups 15, 16 and 17 are tend to obtain electrons from other elements 3, 2 and 1 respectively. The group 18 elements are naturally inert because they do not have valence electrons.

Answer 2

The trend in valency of the Periodic Table generally increases from left to right across a period and decreases down a group. Elements on the left side of the periodic table tend to have lower valencies, while elements on the right side tend to have higher valencies. This is due to the number of valence electrons in the outer shell of the atom.

Answer 3

Down the group --> all elements have same valency

Across the period --> Metals valency increases, non-metal valency decreases