Time taken to complete one oscillation for a pendulum is Time Period, T = 0.5 s
Frequency of the pendulum oscillation = 1 / Time Period => f = 1 / T = 1 / 0.5
Frequency f = 2 Hz
It'll certainly seem like it, because the water will get cold. But cold is not a thing. Heat is. What actually happens is that heat from the water flow into the ice (and melts it).