ions

peroids: they have the same amount of shells, it goes horzintal 

groups: have similar properties as they have they have the same number of electons on thier outer shell 

ions 

you can work out the chrage of an ion by drawing the atom. he aim of each atom is to lose all of its electrons from it outer shell unless its already full 

for example NA 

it has 1 electron on its outer shell this means that its eaier…