Need help with these 2 questions

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.

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions

Calculate the percent composition by mass of each element in al(oh)3. use at least three significant figures.