Question

What is noticeable about all of the ionic charges in Group 1 2 15 16 and 17?

Answer 1

here is your answer

The elements in Group 1,2,15,16 and 17 of the Periodic Table are called the alkali metals. They form ioniccompounds when they react with non-metals. Their ions have a single positive charge. For example, sodium forms sodium ions, Na+

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Answer 2

For the groups on the table, the ion charges are

1 +1 
2 +2 
13 +3 
14 +4/-4 
15 -3 
16 -2 
17 -1 

The ion charge equals the number of electrons gained (-) or 
lost (+) by the atom to form the ion.