Whether an object will float or sink in a liquid, depends on

Whether an object floats or sinks in a liquid is fundamentally determined by the relationship between the density of the object and the density of the liquid. According to Archimedes' principle, an object experiences an upward buoyant force equal to the weight of the liquid it displaces [2]. If the object's average density is greater than that of the liquid, its weight will exceed the maximum possible buoyant force, causing it to sink. Conversely, if the object is less dense than the liquid, the buoyant force will be sufficient to support its weight, allowing it to float. While mass and shape influence the volume of liquid displaced, the ultimate physical criterion for flotation is the difference in densities. This explains why a solid iron rod sinks while a hollow iron ship floats; the ship's overall density is lower than water.

Sources

1. [2] https://www.britannica.com/science/Archimedes-principle