Understanding Electrical Conductivity

Electrical conductivity refers to the ability of a material to conduct electric current. This ability depends on the presence of charge carriers, usually ions or electrons, within the material.

Analyzing Water Conductivity

Water itself, in its purest form (like $H_2O$ molecules), is a very poor conductor of electricity because it lacks free ions. However, most water sources contain dissolved substances, primarily salts and minerals, which dissociate into ions. These ions act as charge carriers, allowing the water to conduct electricity.

Option Analysis:

• Tap water: This water typically contains dissolved minerals and salts added during the purification process (like chlorine compounds) and from pipes. These dissolved ions increase its conductivity, making it a relatively good conductor.
• Water from a pond: Pond water contains numerous impurities, including dissolved minerals, salts from runoff, and organic matter. These contribute ions, making pond water a good conductor of electricity.
• Water from a hand pump: Water drawn from a hand pump often comes from underground sources rich in dissolved minerals and salts. These ions make the water conductive.
• Distilled water: This water has been purified through distillation, a process that removes most of the dissolved ions, minerals, and salts. Because it contains very few charge carriers, distilled water is an extremely poor conductor of electricity.

Conclusion on Conductivity

Based on the analysis, the water source with the least amount of dissolved ions is distilled water, making it the poorest conductor of electricity among the given options.