Answer:
is a 4.095 nitrogen of ammonia
For the element chlorine to be "happy", it needs 8 valence electrons meaning it needs 8 electrons on its outer shell. So the answer would be chlorine because it has 7 valence electrons in the picture and it needs one more to be considered stable.
Answer:

Explanation:
Data:
p₁ = 694.9 mmHg; V₁ = 3.463 L
p₂ = ?; V₂ = 5.887 L
Calculation:

A cation (+) will be smaller than its neutral atom, while anion (-) will be larger than its neutral atom.
It could be a lump of coal.
Since you can break pieces off, maybe charcoal ... the real thing, not a "briquet".
Do your hands get all black when you handle it ?