A stock with a beta of more than one is more volatile than the market. If the market goes up, it tends to go up at a greater magnitude (i.e. market goes up 10%, stock goes up 15%). The higher the beta, the more volatile the stock.
Is a glass of cola a element or a compound or a homogeneous mixture or a heterogeneous mixture? A glass of cola is heterogeneous mixture because the ingredients are physically separate. Just look at the bubbles.
Yes, in chemistry a pure substance means either an element or a compound. Thus, hydrogen, oxygen, sodium, iron, copper etc. are pure substances; and so are compounds such as water, sugar, ammonia, sodium chloride, methane, ethanol etc. A compound is composed of two or more elements combined in a fixed ratio by mass. Like an element, a compound also has a distinct chemical identity. A mixture is not a pure substance as it is a collection of two or more elements/compounds in varying ratio. Air, sea water, gasoline, vegetable oils, steel etc. are mixtures.