Hi!
1) electrons
2) Chadwick
3) J. J. Thompson
4) Bohr
5) Rutherford
6) Dalton
7) Nucleus
I hope this helps!
Answer : The correct option is, 13.7 mole
Solution : Given,
Moles of
= 27.4 moles
The given balanced chemical reaction is,

From the balanced chemical reaction, we conclude that
As, 2 moles of
react with 1 moles of 
So, 27.4 moles of
react with
moles of 
Therefore, the number of moles of oxygen
required are, 13.7 moles
ELECTRON CONFIGURATION
Highest occupied energy level of an element
equal to the period
for example, the highest occupied energy level of He is 1, Be is 2, Al is 3, Ca is 4, and Sn is 5