Periods
Seven periods of elements occur naturally on Earth. For period 8, which includes elements which may be synthesized after 2011, see the extended periodic table.
A group in chemistry means a family of objects with similarities like different families.
Read more about this topic: Period (periodic Table)
Famous quotes containing the word periods:
“At great periods you have always felt, deep within you, the temptation to commit suicide. You gave yourself to it; breached your own defenses. You were a child. The idea of suicide was a protest against life; by dying, you would escape this longing for death.”
—Cesare Pavese (1908–1950)
“How easily and cleverly do I write just now! I am really pleased with myself; words come skipping to me like lambs upon Moffat Hill; and I turn my periods smoothly and imperceptibly like a skilful wheelwright turning tops in a turning-loom. There’s fancy! There’s simile!”
—James Boswell (1740–1795)
“It is noticed, that the consideration of the great periods and spaces of astronomy induces a dignity of mind, and an indifference to death.”
—Ralph Waldo Emerson (1803–1882)