# How do you write the electron dot diagram for the hydronium ion H_3O^+?

Just treat it on the basis of VESPER....you got ${H}_{3} {\ddot{O}}^{+}$
Electronic geometry of ${H}_{2} \ddot{O} :$ is precisely the same as that of ${H}_{3} {\ddot{O}}^{+}$...we conceive that ONE of the lone pair electrons of water donates to an ${H}^{+}$ ion...
${H}_{2} \ddot{O} : + {H}^{+} r i g h t \le f t h a r p \infty n s {H}_{3} {\ddot{O}}^{+}$