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.
An example of a rain shadow. A rain shadow is a dry area on the leeward side of a mountainous area (away from the wind). The mountains block the passage of rain-producing weather systems and cast a shadow of dryness behind them. Wind and moist air is drawn by the prevailing winds towards the top of the mountains, where it condenses and precipitates before it crosses the top.