Answer:
A chair at rest on the floor has two forces acting on it its own weight that pulls it downward and the floor pushing upward on the chair, both of these forces are acting on it but the net force is 0, so the chair remains at rest and its velocity stays at 0.
The correct choice is
B. sublimation, then condensation
Sublimation is the name of the process where a solid directly converts into gas on heating. on heating solid crystals of iodine directly change into gas. hence this is sublimation.
condensation is the process where gas is converted into liquid on cooling.
here iodine gas is being converted into droplets on reducing the temperature. hence this is condensation.
