What is a substance that cannot be separated into simpler substances by physical or mechanical methods such as filtering, boiling, or sifting?

Answer 1

Compounds are such substances that can't be separated by chemical means like potassium chloride, sodium chloride(common salt), potassium aluminium sulphate(alum).

Answer 2

what is the freakin anser

Answer 3

Why does a helium balloon float up?

Answer 4

Because it thought the sun was hot.