I’m not good at this but I’m guessing it’ll be the first one!
Answer : The type of reaction described in the sentence is Synthesis or Combination
Explanation :
The balanced equation for the reaction between Phosphorous and Oxygen gas can be written as

From the above equation we can see that there are two different reactants ( P and O₂ ) which are combining with each other to give a single product.
This type of reaction is known as Combination or Synthesis.
A general form of Synthesis reaction is given below.

Here we can conclude that a synthesis / combination reaction is the one where 2 or more reactants combine together to give only one product .
Answer:
3- is the charge and 8 dots on its Lewis dot structure.
Explanation:
Hello there!
In this case, since nitrogen is an element with five valence electrons (electrons on its outer shell), we infer that it needs three bonds to complete the octet, for which its charge, when forming nitride ions is 3-, which means it has received three electrons. Thus, when drawing the Lewis dot structure, it is evident that is will have 5+3 = 8 dots due to the electron reception.
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