Chemical element same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one stable isotope. For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% Cu and 31% Cu, with different numbers of neutrons. However, a pure gold ingot would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, Au. Atoms of chemically pure elements may bond to each other chemically in
Lacul cu Nămol Lacul cu Nămol Lacul cu Nămol, also called (Lacul) Balta cu Nămol, is a natural salt lake in the town of Ocna Sibiului, Sibiu County, Transylvania, Romania. It is one of the many lakes of the Ocna Sibiului mine, a large salt mine which has one of the largest salt reserves in Romania. In Romanian, "Lacul cu Nămol" means "the Lake with Mud" . The other name of the lake, Balta cu Nămol, means the Pond with Mud. The lake was formed after an excavation of the salt's cover. Lacul cu Nămol and Lacul Negru are the only lakes of