Answer:
Option-A is the correct answer
Explanation:
Lithium belong to group 1 metals. Hence, it can loose one electron to form lithium ion i.e. Li⁺¹ or Li⁺
While, Nitrogen is non-metal and hence has the ability to gain the electron lost by lithium metal. Furthermore, Nitrogen can gain maximum 3 electrons to acheive noble gas configuration. Hence, three Li atoms will loose their electrons and Nitrogen will gain those three electrons to form nitride ion i.e. N³⁻.
Hope this helps! If you dont understand balancing equations in general, say so in the comments, I’m happy to help
Answer:
-100 kJ
Explanation:
We can solve this problem by applying the first law of thermodynamics, which states that:

where:
is the change in internal energy of a system
Q is the heat absorbed/released by the system (it is positive if absorbed by the system, negative if released by the system)
W is the work done by the system (it is positive if done by the system, negative if done on the system)
For the system in this problem we have:
W = +147 kJ is the work done by the system
Q = +47 kJ is the heat absorbed by the system
So , its change in internal energy is:

Stoichiometry is not really hard if you are good with your numbers. All you have to do is pay close attention and follow you teacher because if you don't you will end up like me not knowing what you are doing. Listen and pay real close attention and I can guarantee you it will be just fine!