Diatomic molecules are molecules composed only of two atom s, of either the same or different chemical element s. The prefix di-means two in Greek. Common diatomic molecules are hydrogen (H 2), nitrogen (N 2), oxygen (O 2), and carbon monoxide (CO).he bond in a homonuclear diatomic molecule is non-polar and covalent. In most diatomic molecules, the elements are nonidentical. Prominent examples include carbon monoxide, nitric oxide, and hydrogen chloride, but other important examples include MgO and NaCl.
Africa, which developed the world's oldest human civilization, gave humanity the use of fire a million and half to two million years ago. It is the home of the first tools, astronomy, jewelry, fishing, mathematics, crops, art, use of pigments, cutting and other pointed instruments and animal domestication.In short Africa gave the world human civilization.illions of years ago human life started in Africa, Australopithecus aphaeresis and Australopithecus africanus and Australopithecus robustus were all key rungs in the development of humanity.
Smaller civilizations arose in Elam in modern-day Iran, and on the island of Crete in the Aegean Sea, as well as the Olmec civilization and the Caral civilization in modern-day Mexico and Peru. The Mesopotamian civilization of Sumer is officially is believed to have begun around 4000-3500 BC. It ended at 2334 BC with the rise of Akkad, and is the world's first civilization. The Egyptian civilization of the Nile Valley started at around 3200 BC. It ended at around 343 BC, at the start of the Achaemenid dynasty's control of Egypt. This is one of the three oldest civilizations in the world.