Concept:Phase changes (boiling, melting) involve disrupting intermolecular forces holding distinct molecules together, not tearing apart the molecule itself.
Solution:- A water molecule consists of two H's and one O firmly attached by unbreakable polar covalent bonds.
- However, individual water molecules stick to each other in a liquid state via weaker intermolecular attractions called Hydrogen bonds.
- When water vaporizes (turns to steam), the individual \(H_2O\) molecules remain completely intact. Only the Hydrogen bonds between neighboring molecules are stretched and physically broken to allow them to escape into the gas phase.
Why other options are incorrect:- Covalent / Polar covalent bonds: Breaking these would chemically destroy the water molecule, separating it into explosive Hydrogen and Oxygen gas (electrolysis), rather than just boiling it into steam.
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