Question

a. density: is the mass of substance
b. solubility: is the ability of one material to dissolve in another material
c. chemical property: is the ability or inability of a substance to combine
d. flammability: is a chemical property
reading check

1. explain: how does a material change at its melting point and at its boiling point?

visual check

1. identify: what type of chemical property is show in the figure below?

Explanation:

1. At the melting - point, a material changes from a solid to a liquid state. The particles gain enough energy to break free from their fixed positions in the solid lattice but are still close together in the liquid state. At the boiling - point, a material changes from a liquid to a gas state. The particles gain sufficient energy to completely overcome the intermolecular forces holding them together in the liquid and move freely as a gas.
2. The figure shows a piece of paper on fire, so the chemical property demonstrated is flammability, which is the ability of a substance to burn in the presence of oxygen.

Answer:

1. At the melting - point, a material changes from solid to liquid. At the boiling - point, a material changes from liquid to gas.
2. Flammability.