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 for certain computer uses. "Fern green" is a color that resembles ferns. A Crayola crayon named "fern" was created in 1998, which is a lighter shade of the top color shown on the right. The first recorded use of "fern green" as a color name in English was in 1902. "Forest green" refers to a green color said to resemble the color of the trees and other plants in a forest. The first recorded use of "forest green" as the name of a color in the English language was in 1810. Displayed at right is the color "green earth". "Hooker's