solid → melting → liquid → evaporation → gas
(Note: The reverse processes would be freezing and condensation)

The total kinetic energy decreases as the gas changes to liquid and then to solid. This is because:
1. When gas condenses to liquid, particles lose energy and move closer together
2. When liquid freezes to solid, particles lose more energy and vibrate in fixed positions
3. Temperature decreases during these phase changes, indicating lower kinetic energy

R_f = distance moved by substance ÷ distance moved by solvent front
Assuming dye A moved 2.3 cm and solvent moved 5.8 cm:
R_f = 2.3 ÷ 5.8 = 0.4
(Note: Actual values would depend on the chromatogram measurements)

Dye B cannot be in the ink sample because:
1. The ink sample’s components don’t match the color pattern of dye B
2. In chromatography, a dye present in the sample should produce spots at the same heights as the sample’s components
3. Dye B shows different migration distances compared to the ink’s components

A solvent is a substance (usually liquid) that can dissolve other substances (solutes) to form a solution. In chromatography:
1. It moves up the paper carrying the sample components
2. Different components travel at different rates based on their solubility
3. Common solvents include water, ethanol, or specialized mixtures

Pure substance: X
Explanation:
1. Pure substances melt at a sharp, specific temperature (84°C for X)
2. Impure substances melt over a temperature range (78-82°C for Y)
3. The presence of impurities lowers and broadens the melting point range