Molecules move more slowly in solids because there they are all very compact
C. CaCl2 is the correct answer
Answer:

Explanation:
Given that,
The mass of the rock, m = 15 g
The volume of the rock, V = 10 cm³
We need to find the density of the rock. The density of an object is equal to the mass per unit volume such that,

So, the density of the rock is equal to
.
Answer:
C. C
Explanation:
The heating curve is a graphical representation shows that how different phases of substances change as it is influenced by the increase in temperature or heat.
Section A represents solid phase, Section B represents solid-liquid phase, section C represents liquid phase, section D represent liquid-gas phase and section E represents gas phase.
Section C of the graph shows the liquid phase of the substance gaining kinetic energy. During Phase C, heat energy is absorbed and liquid particles gain kinetic energy to change into gas form that is section E.
Hence, the correct option is C.C.
The molecular polarity and bond type of PCl3 is polar.