At standard atmospheric pressure, the specific temperature at which a substance transitions from a liquid state to a gaseous state is called its:

The correct option is Boiling point.

Step-by-Step Explanation:

Phase transitions refer to the physical processes in which a substance changes from one fundamental state of matter (solid, liquid, or gas) to another upon reaching specific temperature and pressure conditions.

Let us analyze the definitions of each option to understand why Boiling point is correct:

1. Boiling point: This is the precise temperature at which a substance converts from a liquid state to a gaseous state under standard atmospheric pressure. At this temperature, the vapor pressure exerted by the liquid equals the surrounding atmospheric pressure, causing bubbles of vapor to form throughout the liquid.
2. Condensation point: This is the temperature at which a substance changes from a gaseous state to a liquid state as heat is removed.
3. Freezing point: This is the temperature at which a substance undergoes phase transition from a liquid state to a solid state.
4. Sublimation point: This is the temperature at which a substance transitions directly from a solid state to a gaseous state without passing through the intermediate liquid phase.

Thus, the temperature at which a substance transitions from liquid to gas at standard atmospheric pressure is called its boiling point.