Density and Archimedes principle:

• If the object's density is lesser than that of the surrounding fluid, then it will float.

Reasoning: Since the fluid has a higher density, it contains more mass = more weight in the same volume, hence the buoyant force produced is greater. (Buoyant force = weight of fluid displaced)

source: https://courses.lumenlearning.com/suny-osuniversityphysics/chapter/14-4-archimedes-principle-and-buoyancy/#:~:text=If an object's average density,the weight of the object.