Answer: The correct formula for phosphorous pentachloride is 
because a subscript 5 indicates five chlorine (Cl) atoms.
Explanation: For the given molecule, phosphorous pentachloride, there are 2 atoms present which are phosphorous and chlorine atoms.
Number of phosphorous atoms = 1
Number of chlorine atoms = 5
So, the correct formula for phosphorous pentachloride will be because the subscript 5 represents the 5 chlorine atoms.
Trihydrate - basically 3 molecules of water. Unless you're referring to the molecule 3H2O used in measuring the total body water in the case it tritiated water.
Why not search it up and figure it out and then write it how you would?
Answer: Metals are malleable. Most metallic elements are solids at room temperature.
Explanation:
Well if anything was mixed in it would make his result different. if not, it could have changed the temperature when he mixed it. which would give him either a lower or higher answer
