Boiling point of water.

**The reasoning** At sea level (normal atmospheric pressure), water boils at **100°C** (or 212°F). This is when water molecules gain enough energy to escape from liquid to gas (steam). This temperature is a **fixed physical property** of pure water under standard conditions—it's not a guess, it's a scientific constant you'll use throughout Chemistry and Physics. **Why the wrong options tempt you** - **0°C** is water's *freezing/melting* point—students often mix these two key temperatures up during revision pressure. - **50°C** is just warm water (like bath temperature)—some might think "halfway sounds reasonable" but boiling requires much more energy. - **150°C** goes beyond boiling—water would already be steam before this. This traps students who think "higher = boiling." **Quick takeaway** Remember the duo: **0°C freezes, 100°C boils**—these are water's signature temperatures at normal pressure, and they appear in JAMB, WAEC, and practical questions constantly.