16. Which of the following have the same electron configuration as each other? 1. Na+1 and Ar
2. Na+1 and Ne
3. Na and Ne
4. Na and Na+1

Exothermic,  physical change after it is already baked

The correct answer is "hydrogen".

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