Question

select the metals that form only one type of ion (that is, metals whose charge is invariant from one compound to another). check all that apply. na ca w mo pd cu k pb ba cs fe mg rb sr co al li v

Explanation:

To determine metals that form only one type of ion, we refer to the concept of fixed oxidation states. Alkali metals (Group 1: Na, K, Cs, Rb, Li) have a fixed +1 charge. Alkaline earth metals (Group 2: Ca, Ba, Mg, Sr) have a fixed +2 charge. Aluminum (Al) has a fixed +3 charge. Transition metals (like W, Mo, Pd, Cu, Fe, Pb, Co, V) often have variable oxidation states. So we identify the metals with invariant charges: Na (Group 1, +1), Ca (Group 2, +2), K (Group 1, +1), Ba (Group 2, +2), Cs (Group 1, +1), Mg (Group 2, +2), Rb (Group 1, +1), Sr (Group 2, +2), Al (Group 13, +3), Li (Group 1, +1).

Answer:

A. Na
B. Ca
C. K
D. Ba
E. Cs
F. Mg
G. Rb
H. Sr
I. Al
J. Li