Which is the electron configuration for bromine?

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

Non renewable resources like petroleum eventually

Astudent carefully transfers 30 g of water and 30 g of alcohol in a glass tube, forming two layers and filling the tube completely. after sealing the tube, the student mixes the solutions, and notices a bubble that forms in the tube. what is the mass of the contents in the glass tube after mixing?