How many core and valance electrons are in Silicon?

What natural process has worn down Appalachians mountains? Why is decomposition important in a forest ecosystem? What countries does not have volcanoes? What compounds are formed from noble gases? Does root pressure move water a long distance up the xylem because of the higher water potential of the xylem in comparison to the water potential in the surrounding cells? How is the main result of meiosis achieved? How much gas does a 767 burn? How many people escaped mount Vesuvius? What gas do plants eat? What happens if Enzymes is defective and non-functional? Where would a condylar joint be located? If you stop an object moving in a circular path what direction will the object travel an instant later? What is the fastest type of network? Why are the cell bodies of neurons elongated into cell processes? How many feet will you travel going 50 miles per hour? How are liquids are different to gases? What is rapid reading? What does packed closely together mean? How much light does the jungle get a day? Give an example of how mammals were able to differentiate in the Cenozoic era?