In which of these samples do the molecules most likely have the least kinetic energy? a) solid iron at 25°c b) molten iron at 1600°c c) solid iron at 98°c d) iron vapor at 2900°c

Solid iron @ 25°C

Explanation:

First we need to know what kinetic energy is. Kinetic energy is the energy possessed by a body by virtue of its motion. Molecule of an object tends to possess high kinetic energy under high application of heat but possess less kinetic energy when subjected to low temperature. When much larger heat is applied to an object, the molecules of the object tends to vibrate and move away from their mean fixed position and possessing high kinetic energy. In states of matter which consists of liquid, solid and gases, gases tends to possess high kinetic energy than liquid and liquid than solid and this is due to the difference in their intermolecular distance. The distance between the molecules of solid is small compared to other state of matters. According to the above conclusion solid iron @25°C will have least kinetic energy being a solid substance and under the least amount of temperature (heat).

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.