I don’t understand! Please help :( Just answering one of them will be helpful enough. Much appreciated.

For each of the following elements, indicate which set of orbitals is being filled last: tungsten, iron, europium, cerium, uranium.

The answer for this is a

Hbr dissociates to form h+ and br-ca(oh)2 dissociates to form ca2+ and 2oh-the h+ and oh- react to form waterassuming the reactants are dissolved in water, the net reaction is h+ + oh- —> h2oif you’re asked to show all components of the reaction, the complete reaction is 2hbr + ca(oh)2 —> cabr2 + 2h2o

What are the options? physical property can be color, smell, opacity, viscosity, density, infra red spectrum, melting and boiling points, attraction and repulson to magnets, etc.