What is the energy required to excite one na atom (wavelength = 589 nm)? to excite one mole of na atom?

The energy required to excite one Na atom 3.37 x 10⁻¹⁹J 
E = hc/λ
where h = plancks constant  = 6.626 x 10⁻³⁴J·s
and λ = 589 nm = 589 x 10⁻⁹m
and c = 3 x 10⁸ m/s
E = (6.626 x 10⁻³⁴ x 3 x 10⁸) / 589 x 10⁻⁹m 
E = 3.37 x 10⁻¹⁹J 
Energy to excite one mole of na atom = (6.022 x 10²³) x 3.37 x 10⁻¹⁹ = 203kj

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