Noble gas notation for molybdenum:
[Kr] 4d^5 5s^1
Answer:
Explanation:
The given equation is:

Based on the reaction stoichiometry:
2 moles of barium chloride (BaCl2) reacts with 2 moles of sulfuric acid (H2SO4) to form 2 moles of barium sulfate (BaSO4) and 4 moles of HCl
Although the reaction is balanced, the correct convention is to depict reactions in terms of the lowest molar ratio. Therefore the coefficients (2,2,4 and 4) can be divided by 2 to give:
I think the answer is A. Hope that helped :)