Cations A. are charged ions which move toward the cathode of a galvanic or electrolysis cell. B. are charged ions which move toward the south pole of a magnetic field. C. are charged ions which move toward the positive electrode of an electrolysis cell. D. are ions which attach themselves to any electrode to react chemically during electrolysis. E. are negatively charged ions which result from electrical discharge in a liquid solution.

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6

that's what i got you can count the number of atoms