cations
Some elements lose one or more electrons in forming ions. These ions are known as cations because they are positively charged and migrate toward the negative electrode cathode in an electrical field. Looking at the periodic table below, we know that the group 1 elements are all characterized by having one s electron in the outer orbit and group 2 elements have two s electrons in the outer orbit. These electrons are loosely attached to the atom and can easily be removed, leaving more protons in the atom that there are electrons, so the resulting ion has a positive charge. Cations can also be formed from electron loss to many of the transition elements.