Answer:
A)
<u>4, 7, 4, 6</u>
B)
<u>12 moles</u>
Explanation:

__↑______↑
8.00 mol | 14.00 mol
________________

You can turn this into a system of variables which are solvable.
To do this, create variables for the coefficients of each compound in the reaction respectively.

Because to be balanced, the count of atoms in each element of the compound correspond to the coefficient of the variable in that compound so that the count of the left (reactant) side is set equal to the right (product) side.
a corresponds to the coefficient of the first compound, b corresponds to the coefficient of the second compound, c corresponds to the coefficient of the third compound, and d corresponds to the coefficient of the fourth compound.
(Reactant = Product)
Reactant: 1a [N] Product: 1c.
Reactant: 3a [H] Product: 2d.
Reactant: 2b [O] Product: 2c + 1d.
Thus the system is:
1a = 1c
3a = 2d
2b = 2c + 1d.
Then just use the substitution methods to solve.
Answer: BF3
Explanation: boron needs 4 electron to obtain octet and Fluorine has just one. For the valence shell to be completely filled it will have to form BF4- with 4 fluorine atom surrounding it.
If there weren't any predators, the population of prey would increase and they would starve due to too many mouths to feed.