Answer:
Lewis structure of Hydronium ion is shown below :
Explanation:
Lewis structure : It is a representation of valence electrons on the atoms in a molecule
Here , Hydronium ion is given , which contains 1 atom of oxygen and 3 atoms of hydrogen .
Oxygen has a total of 6 valence electrons and hydrogen contains 1 valence electron .
Oxygen share its 3 valence electrons with 3 hydrogen atoms and left with 3 valence electrons. From these three valence electrons of oxygen atom two electrons will be shown as a pair of electrons on oxygen atom but a single electron can not be shown . So , to simplify this, one positive charge is shown overall .
Resonance structure will be same as the hybrid structure because all three atoms are same , that is hydrogen .