The correct answer is D) Ar
Selenium falls in the same column with oxygen therefore it has the same number of valence electrons with oxygen which is 6. It fills the 3d orbital but only 4s and 4p are counted. The electronic configuration is [Ar]3d^10 4s^2.
Answer:
56.28 g
Explanation:
First change the grams of oxygen to moles.
(50.00 g)/(32.00 g/mol) = 1.5625 mol O₂
You have to use stoichiometry for the next part. Looking at the equation, you can see that for every 2 moles of H₂O, 1 mole of O₂ is produced. Convert from moles of O₂ to moles of H₂O using this relation.
(1.5625 mol O₂) × (2 mol H₂O/1 mol O₂) = 3.125 mol H₂O
Now convert moles of H₂O to grams.
(3.125 mol) × (18.01 g/mol) = 56.28125 g
Convert to significant figures.
56.28125 ≈ 56.28
