Question

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

Answer 1

\(\large \color{red}{pure?}\)

Answer 2

a pure is a substance? that doesn't sound right

Answer 3

lol sorry i didn't read it correctly.

Answer 4

"pure substance"?

Answer 5

Here, this link will help.
http://www.ausetute.com.au/puresubs.html