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>
Answer:
That is a compound. If it was an element it would either just be Na or Cl.
<span>lower than the boiling point of water
</span>
Your answer would be C. Alpha decay involves the ejection of 2 protons and 2 neutrons from the nucleus for a total of 4 amu lost. This form of decay is most common in heavy elements.
