B. because you can reuse them.
When Heat is added to it.
Boiling poitns of elements
Answer:
Explanation:The lewis structure of ammonia shows that nitrogen is surrounded by four electron pairs.In term of electron repulsions model,the tetrahedral structure gives maximum separation .There is one lone pair electrons on nitrogen which replels the bonding pairs with the result that angles is reduced from 109 to 107.In term of hybrid orbital.model ,nitrogen utilizes is three of four sp3 orbitals to form sigma bond with three hydrogen atoms having one non bonding orbital on nitrogen.