Physical properties are usually those that can be observed using our senses such as color, luster, freezing point, boiling point, melting point, density, hardness and odor.
What are the Chemical Properties of Hydrogen? They are the characteristics that determine how it will react with other substances or change from one substance to another.
That particular group of elements is reffered to as the "Noble Gasses"--a title that comes from the fact that these gases are very "secure" and don't mix well with other elements.
