WHAT ARE RADIOISOTOPES ? Many of the chemical elements have a number of isotopes. The isotopes of an element have the same number of protons in their atoms (atomic number) but different masses due to different numbers of neutrons. In an atom in the neutral state, the number of external electrons also equals the atomic number.
Ciudad Perdida Archaelological Park (Colombia.travel), also known as Teyuna, is on the Buritaca River in the Sierra Nevada de Santa Marta mountain range. Ciudad Perdida, which means lost city, is not easy to get to but visitors can enjoy the beauty of exotic forests, waterfalls and hanging bridges on the way.ierradentro Archaeological Park. Tierradentro Archaeological Park (colombia.travel) is in a mountainous region in southwest Colombia's Department of Cauca. A popular archaeological site, Tierradentro includes stone statues and underground tombs that reach 29 feet deep.
The great pyramid of ToninÃ¡ in the Mexican state of Chiapas is the tallest pre-Colombian structure that has survived to date. At 75 meters, it is taller than Teotihuacanâs pyramid of the Sun. In fact, itâs been considered one of the largest in all of Mesoamerica, competing only with Tikal and El Mirador in Guatemala.