Nitrogen, oxegyn, and water are nonmetals in the atmosphere and combinations are essential for life on earth
The mass of NaN3 needed to produce 17.2 L nitrogen at STP is calculated as follows
find the moles of N2 produced at STP
At STP 1mole of gas = 22.4 L , what about 17.2 L of nitrogen
by cross multiplication
= (1 mole x17.2 L)/ 22.4 L= 0.768 moles
2NaN3 =2Na +3 N2
by use of mole ratio between NaN3 to N2 (2:3) the moles of NaN3 = 0.768 x2/3 = 0.512 moles of NaN3
mass of NaN3 is therefore =moles of NaN3 xmolar mass of NaN3
=0.512moles x 65 g/mol =33.28 grams of NaN3
Answer : Methane 
does not has any resonating structures or isomers.
Explanation : Methane has tetrahedral geometry where all the valence bonds of carbon are satisfied with hydrogen atoms which are similar to each other. They also do not produce any lewis dot structure. Therefore, methane cannot have resonating structures.
Answer:
D. A pond freezing over is not a chemical reaction, it is a physical reaction.
