What is the different between a particle and an element?

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.

What is the polyatamic ion of borate

An atom of which element reacts with an atom of hydrogen to form a bond with the greatest degree of polarity ?