What is the atomic mass of aluminium?

What is the empirical formula of vanadium 1 oxide given that 20.38 grams of vandium combines with oxygen to form 23.58 grams of the oxide

For the following dehydrohalogenation (e2) reaction, draw the zaitsev product(s) resulting from elimination involving c3–c4 (i.e., the carbon atoms depicted with stereobonds). show the product stereochemistry clearly. if there is more than one organic product, both products may be drawn in the same box. ignore elimination involving c3 or c4 and any carbon atom other than c4 or c3.

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.