Tom Skerritt : Tobias. Tom Skerritt, Best Actor EmmyÂ® winner for his series âPicket Fences,â is one of the most versatile and acclaimed American actors of movies and TV. At UCLA Film School, he acted in theatre and began writing for screen as a means to understand the full embrace of his primary interest, directing film.
#Na_3N#. Sodium is an element in group 1 of the periodic table. As such, it will form an electron by losing a single electron to form a #1+# ion: #Na^+#. Nitrogen is an element in group 5 of the periodic table. When it forms the nitride ion, it gains three electrons to form a #3-# ion: #N^(3-)#. In ionic compounds, the charges of constituent ions must balance. This can be achieved by having three sodium ions per nitride ion. Therefore, the formula of sodium nitride is #Na_3N#.
The idea here is that you need to use the chemical formula for magnesium nitride, #Mg_3N_2#, to calculate the mass of one mole of the compound, i.e. its molar mass. So, magnesium nitride is an ionic compound made up of magnesium cations, #Mg^(2+)#, and nitride anions, #N^(3-)#. The subscripts used in the compound's chemical formula tell you how many ions you get in one formula unit of magnesium nitride. In this case, you have.