I think the correct answer is option 3. CaCl2 is the compound that is an electrolyte when dissolved in water. An electrolyte is a substance that conducts electricity in solution. Calcium Chloride when in solution dissociates into ions which allows the flow of current in the solution.
They all have the same number of protons but different numbers of neutrons.
Explanation:
Elements will always have the same number of protons no matter the isotopes. Isotopes only change the number of neutrons. Silicon will always have 14 protons. So silicon-28 has 14 protons and 14 neutrons. Silicon-29 has 14 protons and 15 neutrons. Silicon-30 has 14 protons and 16 neutrons.
