Why does the density for sample of a substance typically decrease as it changes from the solid to liquid state and decrease as it changes from the liquid to gaseous state?

Explanation:

The density of substance is the ratio of mass to volume.

For solids it is maximum ans decreases from solid to liquid to gases.The ratio decreases as the distance between the molecules increases and hence volume increases consequently density decreases. Inter molecular distance is maximum to minimum from solid to gases.

answer: option (b) is the correct answer.

explanation:

a covalent bond is formed by sharing of electrons. whereas polarity arises due to difference in electronegativity of two atoms.

therefore, more is the electronegativity of an atom which combines with the titanium, more readily it will induce a partial positive and negative charge.

thus, out of the given options fluorine is most electronegative and has an incomplete octet. therefore, it will readily combine with titanium to share the electrons and complete its octet.