Which is a characteristic of all ions? a. they are made of one type of atom. b. they have one overall charge. c. they are made of two or more types of atoms. d. they have two or more overall charges.

Answer : The correct option is, They have one overall charge.

Explanation :

All the ions must have one overall charge that means the charge on ion can either a positive or a negative.

They are made of one type of atom : This statement is incorrect because the ions can be made of one or more types of atoms also.

They have two or more overall charges : This statement is incorrect because the charge on ions can either be a positive or a negative.