why does the density of a solid increases with decreasing temperature?
82591
As the solid decreases, the molecules pack together tighter.  Therefore the volume they take up becomes smaller.  The mass however remains the same.  Because density is equal to mass divided by volume, the smaller the volume, the bigger the density.
137292
You didn't really give me too many options with this one.  Increase or increase?  I think I'll have to go with "increase."\nSeriously, if a pipet is dirty, most likely it is contaminated with a salt compound, which would contribute to the density of something you were measuring out with the pipet.
279129
the density of water is 1 gm/cc.however the density of ice is less than 1gm/cc.this means that d density of water of water increases when it changes to ice.this is known as anomalous expansion of water.
747351
It's not heat that rises, it's hot substances. Heat itself has no mass and does not care where the gravity is pointing. However, the density of substances will vary with temperature. Most substances have a decrease in density as the temperature of that substance rises.\n\nThis is why it appears as if heat rises from a fire or your stove. The heat you feel is actually hot air that rises due to the force caused by bouyancy. This bouyancy is a result of the fact that warm air is less dense than cold air.
280201
Density = mass/volume
312206
Water continues to become more dense as it cools until just above the freezing point.  I can't remember the exact temperature off-hand, but I believe it is very near 33.5 to 34 degrees Fahrenheit.  \n\nBelow that water begins to expand and once it has frozen, its volume increases approximately 10%...that's why ice floats...less dense than the water it came from!  Cool, huh?
1043479
...because their density is less than water density (1000 Kg/m^3).\n\nIf the density of an object is less than the density of the water, it floats on the surface of the water. If the density of the object is equal to the density of the water, the object floats anywhere inside the water. If the density of the object is more than the density of the water, the object sinks to the bottom.
162268
The density of the fluid and the density of the object.
302984
I Dont know what sumink is, but if you want to increase the density of any object while keeping its mass constant, its volume has to become smaller (more compact, more dense), hense its radius would decrease as well.
349930
it's because of elasticity(bulk modulus).The force on the surface will try to reduce the volume and but as the volume changes, there is a net upward force and an eqilibrium will be reached when outward (volume)elastic force equals the downward cohesive force. But the decrease in volume and hence the level of warer is so small(in the order of micrometre) that we don't notice it.
882394
Density=Mass/volume, Therefore heating a gas increases its volume. This change has to be compromised by either mass or density. Mass cannot vary as it's a constant, so the density has to give way. Hence the change in density. When volume increases, density decreases as they are inversely proportional.
509909
4°C, the temperature of maximum density for water.\n\nBelow that temperature, and the water starts to expand as the crystalline lattice begins to form.  Above that temperature, the density drops because of the increased molecular vibrational activity.
762753
The interactions between the carbon dioxide molecules are stronger, and thus it forms a solid at a higher temperature.\n\nIn water, the attractions are even stronger and you only need to go to zero degrees to get a solid. If you go to 100 degrees water becomes a gas. (temperatures in celcius)\n\nSimilarly for other molecules, if the atrraction between them is strong you get solids and liquids at higher temperatures than for less cohesive molecules.
236269
Because the atoms in heated water are farther apart.  It actually makes the water less dense.  It then becomes easier to freeze less dense liquid.
706444
Density= Mass/Volume.  When water freezes, its volume increases. This is why a frozen bottle of water expands to the point of bursting. By the formula, if volume increases and Mass stays the same, then the value of density decreases.  Thus, this is why ice floats and is less dense than water.  When the ice melts, the reverse happens in that its volume decreases and again by the formula, density will increase.   Tahdaaaa!!
399680
As the temperature of a liquid increases the particles have more kinetic energy and can move more freely so an object passing through the liquid will experience less friction.
501359
yeaaaaah\n\nit's "expand and rise"\nthe energy (heat) supplied to it causes the individual molecules to have more energy and because of it, they expand further, and rise since density is lowered and volume is increased