Which of these groups contains the most elements? nonmetals , metals , transition , elements , metalloids

Which of these will change if the air in aclosed bottle is heated? abcdthe mass of the airthe composition of the airthe air pressure in the bottlethe number of air molecules in the bottle

Which of the following molecules is polar? c3h7oh c2h5cooh

Which part of the mantle is similar to the crust ? (science)