[t-wes]

  What is the density of water vapor at STP? If I have a piece of ice (a cube), and I let it melt and then i vaporize it, would all three have the same mass?



Thank you

[Arkcon]

  What is the density of water vapor at STP?

Google: Water Vapor STP.  Easy.

If I have a piece of ice (a cube), and I let it melt and then i vaporize it, would all three have the same mass?

Conservation of matter definitely applies to phase change.  It would be a pretty farked up planet if melting or freezing ice caused some to disappear, who'd refill all the lakes?

Thank you

Stay groovy.

P.S.  We tend to use the Socratic method of teaching around here, you know, answer a question with a question, that leads you to the answer.  Try to show us some work.

P.P.S. Please don't crosspost, anyone who clicks on your name can see you've asked the same question earlier today, just slightly rephrased.