They talk about comparing the same volume of ice and liquid water, e.g. 1 cm³ ice vs. 1 cm³ liquid water, not two specimen of the same mass.
Comment on Is ice heavier than water?
DrBob@lemmy.ca 2 days agoDensity is mass by volume. The volume changes because of the crystalline lattice. The mass doesn’t change. I’m trying to decide if you’re trolling or not.
Successful_Try543@feddit.org 2 days ago
TheRealKuni@piefed.social 2 days ago
They aren’t wrong. You’re keeping the mass constant, they’re keeping the volume constant.
I think the confusion might come from their phrasing: “the same volume of ice as water,” which could mean “the same volume of ice as the volume of water” (which is what they meant), but could also be interpreted as “the same volume of ice in the form of water.” The latter interpretation doesn’t fit the rest of their sentence though, so we can safely assume they meant the former.