21,22,23,24,25,26,27,28,29,39, on the table
Answer: 6.38 moles of
are needed to react with 2.55 mol of 
Explanation:
The balanced chemical reaction for the combustion of ethyne is:

According to stoichiometry:
2 moles of
require = 5 moles of 
Thus 2.55 mol of
require =
moles of 
Thus 6.38 moles of
are needed to react with 2.55 mol of 
C. 6 Valence electrons. Remember that the family that they are in will determine the number of valence electrons that element will have. Sulfur is in family 16 so it will have 6 Valence electrons.
Answer:

Explanation:
When a chemical change happens or chemical reaction happens something yields at reactants and something at products
Representing them is called chemical equation