Answer: Number of molecules of hydrogen gas 
Explanation:

Number of moles of sodium =
According to reaction , 2 moles of sodium produces 1 mole of hydrogen gas , then 2.11 mol of sodium will=
of hydrogen gas that is 1.05 moles of hydrogen gas.
Number of molecules =
moles of substance
Moles of hydrogen gas formed = 1.05 moles
Number of molecules of hydrogen gas =
moles of hydrogen gas
Number of molecules of hydrogen gas 
The particles that combined in the middle of the structure best describes neutron as neutron is always present in the middle of atomic structure
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It is also one of seven wonders of the world that is under world heritage. Pyramids where only found in Egypt and nowhere else.
Answer:
Coefficient of 
Coefficient of
=8
Explanation:
We are given that a reaction in which
reacts with 
We have to find the coefficient of each reactants in balanced reaction

Coefficient is defined the constant value multiplied with a reactant in a reaction.
Coefficient of
=3
Coefficient of 
Coefficient of 
Coefficient of 
Coefficient of 
Coefficient of KOH=2
Hence, Coefficient of
and coefficient of 