What is the valence electron configuration for the bromine atom?

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

What is the formula of the ionic compound composed of calcium cations and chloride anions