Mass % of nitrogen = mass of nitrogen*100 / total mass
= 14*100 / (1+ 14 + 32)
= 14*100 / 47
= 29.7 %
Barium Chloride
Aluminum Iodide
Lithium Phosphide
Sodium Nitride
Potassium Sulfide
Aluminum Oxide
Sodium Oxide
Rubidium Bromide
Calcium Phosphide
hope this helps for the names
Dimitri Mendeleev was the first to put elements together on a table. He knew there were elements missing but he noticed a trend in some of the elements known at the time. Sodium, Lithium and other alkali metals all have the same properties so he put them under the same column and created other columns with similar attributes (Halogens, Noble gases, Alkaline earth metals). Over the years, new elements were discovered and put into the rough outline that Mendeleev created.
I hope that is about what you wanted.
Its a compound because they come together
