it doesn't it raises the average energy a particle has. that's temperature not heat.
When a substance is heated it's volume will increase.
No.
That usually means that when you heat a substance, it will expand - its volume will increase.
expand
Normally when you heat a substance its volume increases while mass stays the same. It may not be noticable but the density would decrease.
The volume will increase as the fluid is warmed up.
reduce the volume of the substance by compression or increase the volume of the substance by decompression This assumes the substance is compressible, such as air. In the case of water, you can't.
"Any object, wholly or partially immersed in a stationary fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object." (Archimedes) And this is independent on the heat.
volume,temperature change,specific heatcapacity
then the temperature either goes up or down. When you add heat to a substance the substance normally spreads out more for on a subatomic level the atoms vibrate more. Gases have a larger volume at the same pressure and fluids can increase in volume too. Solids normally expand. The opposite to the above is true with a decrease in temperature. It is good to note that if you melt ice it decreases in volume which is proof that heat dose not always expand the substance.
Volume
They speed up.