Final answer:
The physical properties of a substance, including its phase and boiling and melting points, depend on the strength of its intermolecular forces and the kinetic energy of its molecules, while chemical properties pertain to a substance's reactivity.
Step-by-step explanation:
The student question seems to be asking about specific impulse, which is actually a concept in physics related to rocketry, not strictly limited to the physical properties and chemical reasons that pertain to phases of matter. However, assuming that the student is referring to the latter, the physical properties of a substance include its phase (solid, liquid, gas) and aspects like melting point and boiling point, which are directly influenced by intermolecular forces (IMFs) and the kinetic energy (KE) of its molecules. IMFs consist of various electrostatic attractions that hold particles within a substance close together. KE, which increases with temperature, enables these particles to overcome the IMFs and change their physical state. Melting and boiling points are good examples of physical properties that reflect the strength of IMFs within a substance, with high melting and boiling points indicative of strong IMFs.
For example, ionic compounds generally have higher melting and boiling points compared to covalent compounds because the electrostatic forces between ions (ionic bonds) are much stronger than the IMFs present in covalent compounds. Conversely, the chemical properties of a substance refer to its ability to undergo chemical reactions and form new substances, such as the ability of fluorine to react with most substances and cause metals to burn with a bright flame.