Which is the electron configuration for bromine?
1s22s 2p 3s23p 4s3d104p5
1s22s 2p 3s 3p 4s%3d104p
1s²2s22p 3s?3p 4s%3d104p5
1s22s²2p%3s23p4523d4p5
HURRRY

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

points

explanation: