Question

as temperature increases, density decreases?

Answer 1

of liquids and gasses it does, but in solids it doesnt

Answer 2

Density is inversely proportional to temperature which means that when density increases temperature decrease and vice versa

Density=Mass/Volume

Answer 3

@Kryten I guess the density of solids also decrease with increasing temperature.

Answer 4

@ujjwal it does decrease but its negligible!

Answer 5

so therefore: Density is inversely proportional to temperature
holds true!

Answer 6

This holds true for most materials.. Since, usually, molecules that are heated move faster and drift further apart, the density becomes lower.. However, there are some substances which do not hold to this. personally, I've worked with a hydro-gel which was liquid at low temperatures (below 10 degrees celcius) and became a gel at higher temperatures (around room temperature depending on the concentration of gel polymer).. This material had a higher density at higher temperatures.. I should note that I do not know any natural substances which do this but there are several engineered polymers which have this incredibly cool (at least i think it's cool) attribute.