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.
Humans first appeared on Earth during the Paleolithic Era, in the steppes and savannah of Africa, before migrating to Eurasia, the Americas, and Australia. These humans were hunter-foragers, changing their tools and culture to adapt to their surroundings.