When there is a ionic bond, one element steals or takes away an electron from the other element.
An example is NaCl
In this compound, Chlorine atom steals an extra electron from Sodium to fill its outer shell. So, this is a Ionic bond. Since, the Sodium compound gives away an atom, it is positively charged. Since, Chlorine steals an atom, it is negatively charged. Opposite charges attract, so they become a compound.
When positive and negative mix, it becomes neutral.
Manipulation of the independent variable should change the dependent variable, the value of which "depends" on the independent variable's change in value.