Answer:
All substances can be characterized by their unique sets of physical and chemical properties. Properties that can be determined without changing the composition of a substance are referred to as physical properties. Characteristics such as melting point, boiling point, density, solubility, color, odor, etc.
B. Biomass
(I guess so cause other ones are already being used)
Answer:
The atoms share some of their outer electrons so that each atom has a stable noble gas arrangement.
Explanation:
A model showing that gases are made from the matter of particles that are too small to see and are moving freely around in space can explain many observations.
Because at atmospheric pressure the boiling point is below room temperature, just like Oxygen, Nitrogen etc