Any object or substance that is less dense than a fluid will float in that fluid, so hot water rises (floats) in colder water. Any object or substance that is more dense than a fluid will sink in that fluid, so cold water sinks in warmer water.

In hot water, the food coloring diffuses (spreads out) through the water quickly. In cold water, the food coloring diffuses (spreads out) through the water slowly. The hot water causes the food coloring to diffuse faster. At higher temperatures, particles move faster.

about 30 seconds

Heating matter causes particles in that matter to speed up; cooling matter causes the particles to slow down. Eventually, this leads not only to more (or less) heat and higher (or lower) temperatures, but phase changes, which you’ll read about shortly.

Hotness is due to the high temperature and hence high kinetic energy of molecules in it. And Coldness is due to the very low temperature and hence very low or negligible kinetic energy of molecules in it.

heat is the total energy of the motion of the molecules inside the object or particle, whereas Temperature is merely a measure of this energy. The relationship could be, the more heated an object is there higher the temperature the object will have.

Heat and temperature are two different quantities. The basic difference between heat and temperature is that Heat is the form of energy that transfers from a hot body to a cold body. Its unit is the joule. While the temperature is the degree of hotness and coldness of the body.

The quality of the conductor determines how quickly, and how much of the heat is transferred. The higher the temperature difference, the faster the heat flow and the higher the conductivity of the conductor, the faster the heat flow.

Conduction transfers heat energy in solids. The moving particles of a warm soild material can increase the heat energy of the particles in a cooler solid material by transferring it directly from one particle to the next.