What is a strong electrolyte?

A strong electrolyte is defined as a substance that completely dissociates into ions when it is dissolved in water. This complete dissociation means that a strong electrolyte breaks down entirely into its constituent ions, which allows for highly efficient conduction of electricity in the solution. The presence of free-moving ions is essential for electrical conductivity; therefore, substances like strong acids (e.g., hydrochloric acid) and strong bases (e.g., sodium hydroxide) are typical examples of strong electrolytes.

In contrast, other types of substances do not exhibit complete dissociation. For instance, a substance that partially dissociates into ions would be categorized as a weak electrolyte. Moreover, a substance that remains undissolved in solution or does not conduct electricity would not qualify as an electrolyte at all, let alone a strong one. Thus, the identification of a strong electrolyte relies fundamentally on its ability to fully break down into ions, making option B the correct answer.