How do you find which compounds are electrolytes

Question

How do you find which compounds are electrolytes, nonelectrolytes, strong electrolytes, weak electrolytes?

In HNO₃ solution, only H⁺ and NO₃^- are found, no HNO₃ molecules.

In CH₃COOH solution, much greater amount of CH₃COOH molecules and some H⁺ and CH₃COO^- ions are found.

In C₃H₇OH solution, only C₃H₇OH are found.