Answer
$H_2O$ has two hydrogen atoms single-bonded to an oxygen atom. The molecular geometry is bent, and the bond angle is $104.5^{\circ}$.
Work Step by Step
$H_2O$ has a tetrahedral electron arrangement due to the oxygen atom's $sp^3$ hybridization. Since 2 of those $sp^3$ hybrid orbitals hold lone pairs, only 2 of the $sp^3$ hybrid orbitals form bonds. Therefore, the molecular structure is bent. Since the non-bonding pairs effectively take up more space than the bonding pairs, the bond angle is slightly less than $109.5^{\circ}$ bond angle it would have if it were perfectly tetrahedral.
