So for this example question, it says from what you know about ion formation in the periodic table, which ion would be unlikely to occur. So before we look at this question, remember we're going to say that metals, they tend to lose electrons, so if they're going to lose electrons, they're going to become positively charged. And remember, nonmetals tend to gain electrons and therefore become negatively charged.
So if we take a look here, we have RB looking on a periodic table. We know that RB hat is a metal and therefore it makes sense that it would have a positive charge. So this is a likely setup for RBI. Next, oxygen O oxygen is a nonmetal. Nonmetals tend to gain electrons and become negatively charged, so this is reasonable.
Minnesota Minnesota is a metal. Again, metals tend to lose electrons to become positively charged, so that positive charge is a possibility. Al Al is aluminum. Aluminum is a metal. Again metals tend to lose electrons to become positively charged so it doesn't make sense that Al would have a Al-3 charge here. So this is unlikely. So this would be our answer then if we look at the last one, CL chlorine, chlorine is a nonmetal so it makes sense it could gain electrons to become negatively charged.
So just Remember Remember metals tend to lose electrons to become positively charged. Non metals tend to gain electrons to become negatively charged. OK, now that we know this fundamental idea, let's move on to our next video where we go into how many electrons do they gain? How many electrons do they lose? And in that way know what type of ions are possible for certain types of elements.