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.
This is known as a seismic shadow zone, and it provides geologists insight into the properties of the inner core. The change in seismic waves gives seismologists the chance to peer into the layers of the Earth and gain insight into the inner core. Seismologists discovered that primary waves refract (bend) as they travel through different materials.