Question

Which cannot be separated into simpler substances by physical or mechanical methods such as filtering, boiling, or sifting?
A. a crystalline solid
B. a sublimation
C. a pure substance
D. an amorphous solid

I think it is A am I right?

Answer 1

anyone?

Answer 2

I don't think it's A.

Answer 3

A is incorrect. Please re-read this question carefully and when you're done, please try again.

Answer 4

what is the correct answer then?????