An atom has 6 valence electrons and 2 energy levels of electrons. What element is it?

What is the mass of sodium in 3 moles of sodium chloride

One of the few xenon compounds that form is cesium xenon heptafluoride (csxef7). how many moles of csxef7 can be produced from the reaction of 13.0 mol cesium fluoride with 12.5 mol xenon hexafluoride? csf(s) + xef6(s) csxef7(s)

How many grams of aluminum will there be in 98g of al2o3?