Question

An ice cube at zero degree Celsius place in some liquid water ice cube sinks.Why?​

Answer 1

Ice cubes don’t sink in water, they float.

If you add water to a bucket full of ice, then some of the ice will melt, bringing the water temperature down to 0 degrees Celsius. Every gram of ice that melts will reduce the temperature of 80 grams of water by one degree.

Once the water is at 0 degrees, the rate at which the ice melts will slow down as it will have to adsorb [thermal] energy from outside the bucket, not from the water itself.

Answer 2

The ice cubes only float and not able to sink in the water. ... The ice melts slow down because of the absorption of the thermal energy. The ice melts can minimize the temperature of the water by a single degree.