Here is the answer for the three of them
<span>N20 = 16 e-
</span><span>SeCl2 =20
</span><span>PBr3 = 26
Remember that t</span><span>o find the valence electrons in an atom you need to identify what group the element is in. An element in group 1A has 1 valence electron. If the element is in group 2A, then it has two valence electrons.</span>
Moles of PF₃ : 4
<h3>Further explanation</h3>
A reaction coefficient is a number in the chemical formula of a substance involved in the reaction equation. The reaction coefficient is useful for equalizing reagents and products.
Reaction

1.25 moles of P₄(s) is reacted with 6 moles of F₂(g)
Limiting reactant : the smallest ratio (mol divide by coefficient)
P₄ : F₂ =

mol PF₃ based on mol of limiting reactant(F₂), so mol PF₃ :

Answer:
C. It is hard to recreate the extremely high temperatures and pressures found inside stars.
Explanation:
Nuclear fusion occurs when atomic nuclei are forcefully combined to create a new atomic nuclei or subatomic particles. In nature, this process takes place in our Sun and other stars. Within stars, extremely high temperatures and pressures are achieved and cause nuclear fusion to occur. Humans have not yet been successful in recreating the environment necessary to mimic this process.
Answer:
There are two types of cell division: mitosis and meiosis. Most of the time when people refer to “cell division,” they mean mitosis, the process of making new body cells.
The correct answer is D) Ar