Chemical element whole number. For example, the relative atomic mass of chlorine is 35.453 u, which differs greatly from a whole number as it is an average of about 76% chlorine-35 and 24% chlorine-37. Whenever a relative atomic mass value differs by more than 1% from a whole number, it is due to this averaging effect, as significant amounts of more than one isotope are naturally present in a sample of that element. Chemists and nuclear scientists have different definitions of a "pure element". In chemistry, a pure element means a substance whose atoms all (or in practice almost all) have the
Shades of green green" is a dark green color created by mixing Prussian blue and Gamboge. It is displayed on the right. Hooker's green takes its name from botanical artist William Hooker (1779–1832) who first created a special pigment for leaves. Displayed at right is the color "jungle green". In 1990, Crayola named and formulated this specific tone of jungle green. The first recorded use of "jungle green" as a name of a color in the English language was in 1926. "Laurel green" is a medium light hue of greenish gray similar to asparagus, but lighter. The first recorded use of "laurel green"