1. **State the problem:** Find the exact radian measure of the angle between the hour hand and the minute hand of a clock at 7 o'clock.
2. **Formula and rules:**
- Each hour on the clock represents an angle of $\frac{2\pi}{12} = \frac{\pi}{6}$ radians.
- The minute hand at 0 minutes points at 12, which is 0 radians.
- The hour hand at 7 o'clock points at 7 hours.
3. **Calculate the angle:**
- Angle of hour hand from 12:00 is $7 \times \frac{\pi}{6} = \frac{7\pi}{6}$ radians.
- Angle of minute hand from 12:00 is $0$ radians.
4. **Find the difference:**
$$\text{Angle difference} = \left| \frac{7\pi}{6} - 0 \right| = \frac{7\pi}{6}$$
5. **Adjust to the smaller angle:**
- The clock is circular, so the smaller angle between hands is the minimum of the angle difference and $2\pi$ minus the angle difference.
- Calculate $2\pi - \frac{7\pi}{6} = \frac{12\pi}{6} - \frac{7\pi}{6} = \frac{5\pi}{6}$.
- The smaller angle is $\frac{5\pi}{6}$ radians.
**Final answer:** The exact radian measure of the angle between the hour and minute hands at 7 o'clock is $\boxed{\frac{5\pi}{6}}$ radians.
Clock Angle 0038E2
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