Answer:
-7.34 kilo Joules is the change in enthaply when 20.0 grams of nitrogen triiodide decomposes.
Explanation:
Mass of nitrogen triiodide = 20.0 g
Moles of nitrogen triiodide = 

According to reaction, 2 moles of nitrogen triiodide gives 290.0 kilo Joules of heat on decomposition ,then 0.05063 moles of nitrogen triiodide will give :

-7.34 kilo Joules is the change in enthaply when 20.0 grams of nitrogen triiodide decomposes.
you have to show us the rest of it because we have no idea what your looking at. I'm sorry
Ok I may be young but combine the two reactions to create a compund
Yeah of-course!! It's valency by group most of the chemical property like electronegativity, ionization energy etc. by the combination of groups and periods...
Answer:
Tetrahedral electron geometry and trigonal pyramidal molecular geometry.
Explanation:
The Lewis structure is shown in Figure 1.
The central N atom has three bonding pairs and one lone pair, for <em>four electron groups</em>.
VSEPR theory predicts a tetrahedral electron geometry with bond angles of 109.5°.
We do not count the lone pair in determining the molecular shape.
The molecular geometry is trigonal pyramidal (see Figure 2).