6 How do atoms absorb & emit light? â¢ Key idea: Energy â¢ A photon carries energyâ¢ Electron in orbit has energy because it is moving and it is pulled by nucleus. â¢ When atom absorbs photon, energy of photon promotes electron to higher energy.
Until now, researchers believed that homo sapiens, the direct descendants of modern man, evolved in Africa about 200,000 years ago and gradually migrated north, through the Middle East, to Europe and Asia.
In the Paleolithic Age (Paleolithic means old stone) 2 million to 10,000 years ago, Homo sapiens evolved, originating in Africa. Humans spread from Africa roughly 75,000 years ago and developed speech and fire before the Neolithic.