Question

valencies if all elements

Answer 1

it. will be 1,2,3,4. -1,-2,-3,-4

Answer 2

the valency of any element depends on the no of atoms in its outermost shell. For example if an element has 1,2,3 electrons in its outermost shell, then its a metal and has valency +1,+2,+3. If an element has 4,5,6,7 electrons in its outermost shell then it is a non-metal and has the valency -4,-3,-2,-1 etc