Chemistry / Unit 2 Chem 0297 short lesson, about 20 seconds
Predicting Monatomic Ion Charge from Group Number
Captions available
The idea
Main-group metals tend to lose electrons to match the nearest preceding noble gas; nonmetals gain electrons to match the nearest following one.
In practice
Calcium, group 2, loses two electrons to form Ca2+; bromine, group 17, gains one to form Br−, each matching a noble gas.
Where people slip
This trend weakens toward the table's center, where transition metals often form charges the pattern cannot predict.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Something wrong in this lesson? Flag it · Sources for Chemistry