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
Westward the Course of Empire Takes Its Way the 1995 computer game "Oregon Trail II" depict the study version of this painting on the title screen. Westward the Course of Empire Takes Its Way Westward the Course of Empire Takes Its Way (also known as Westward Ho) is a painted mural displayed behind the western staircase of the House of Representatives chamber in the United States Capitol Building. The mural was painted by Emanuel Gottlieb Leutze in 1861 and symbolizes Manifest Destiny, the belief that the United States was destined for Western exploration and expansion originating from the initial colonies along the Atlantic seaboard to the Pacific Ocean.