Which best describes a compound such as sodium chloride?

a pure substance that can be separated into different elements by physical means

a mixture of two common substances that can be separated by chemical means

a mixture of two common elements that can be separated by physical means

a pure substance that can be separated into different elements by chemical means

The second option is the answer. This is a mixture of two common substances that can be separated by chemical means.

NaCL is a compound that was formed through a chemical reaction between sodium and chlorine. In that reaction sodium which is a toxic metal combines with chlorine, a poisonous gas, to form a harmless but totally new compound NaCl or table salt.

Since the sodium ions have a positive charge and the chlorine ions have a negative charge, they are attracted to each other to form an ionic bond.

Sodium can only be separated from Chloride by chemical means e. g. electrolysis.