How many atoms of NITROGEN (N) are represented in the following formula?

Write the formula for the following chemicals. 7. e. trinitrogen tetraoxide a calcium phosphate f. magnesium acetate b. potassium sulfide g nickel(iii) cyanide c carbon dioxide h. silver sulfate d. cobalt(ii) chloride

Answer asap : ( a. how does mucus prevent the entry of pathogens? b. describe two ways white blood cells protect us from pathogens.

Which material burns faster? metal aluminum