Answer:
Groups II and VI
Explanation:
Hello.
In this case, regarding cations from groups I whose oxidations states are +1, II whose oxidation states are +2 and III whose oxidation states are +3 we can see that when they combine with nonmetallic anions they exchange the charges via subscripts. In such a way, when bonding for instance calcium ions with sulfide ions, we obtain:
[tex]Ca^{2+}S^{2-}=Ca_2S_2[/tex]
Which can be simplified to give:
[tex]CaS[/tex]
If we do the same for oxygen, selenium and tellurium, we find the same form since nonmetals from group VIA could form anions with -2 as they need two electrons to attain the octet, therefore, answer is groups II and VI.
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