In one mole, there are 6.022 x 10 23 atoms. Here's another way: there are 6.022 x 10 23 atoms of carbon in 12 grams of carbon-12. Let's say that real clearly: one mole of ANYTHING contains 6.022 x 10 23 entities. The word entities is simply a generic word.
Shadow zone. A seismic shadow zone is an area of the Earth's surface where seismographs cannot detect an earthquake after its seismic waves have passed through the Earth. When an earthquake occurs, seismic waves radiate out spherically from the earthquake's focus.
What is UMBRA? Region of complete shadow of an illuminated object, eg dark central portion of the shadow of the Earth or Moon. Generally applied to eclipses of the Moon or of the Sun, the term is also applied to the dark central portion of a sunspot. The outer, less dark, shadow is known as the penumbra.