Answer:
Explanation:
A) Hg is mercury, a metal that is mostly liquid at STP (Standard Temp and Pressure), though some small portion of it will be gaseous in a closed container.
B) CH Methylidyne radical is a gas
It is not a stable compound because carbon has four valence electrons and only one of those is kept occupied by the hydrogen atom.
If this is supposed to be CH₄ which is methane, then also a gas at STP
C) C₂H₅OH is ethanol which is mostly a liquid at STP, though some small portion of it will be gaseous in a closed container.
D) H₂O is water and will be mostly liquid at STP, though some small portion of it will be gaseous in a closed container.