Final answer:
CH4 (methane) and H2O (water) have the same bond angles but different molecular shapes due to hybridization. Methane has a tetrahedral shape with bond angles of 109.5°,
Step-by-step explanation:
The reason why CH4 (methane) and H2O (water) have the same bond angles but different molecular shapes is due to the concept of hybridization. When atoms are bound together in a molecule, their wave functions combine to produce new mathematical descriptions called hybrid orbitals.
In the case of CH4, carbon forms four equivalent hybrid orbitals that point towards the corners of a tetrahedron, resulting in a tetrahedral shape with bond angles of 109.5°. On the other hand, in H2O, oxygen forms two hybrid orbitals and two unhybridized p orbitals.
The hybridized orbitals form a bent shape with bond angles of 104.5°.