because some objects are much denser(heavier) than water so they sink
Because some objects are a lot denser than water so the sink and others are less denser so they float
Because some objects are heaver than others.
No, some sink.
It's far from clear what the actual question is. Some objects float in both salt and fresh water, some objects float in neither, and some objects float in one but not the other. Any object that floats in fresh water will float in salt water, but the reverse is not true.
The types of objects that will float on water are foil, most rubber, and some plastic.
The density of water is called "1.0" Certain objects have a mass greater than 1.0, therefore they will sink. Objects with densities less than 1.0 will float or remain partly submerged.
It is to do with to volume and mass.
Objects float in water if they have a density lower than water, while objects sink if they have a density higher than water. Density is a measure of how much mass per unit volume an object has. This is why objects like wood and plastic, which have lower density than water, tend to float, while objects like metal, which have higher density, tend to sink.
On some liquids it will float, on others it will not.
Styrofoam
Some objects that float on milk are coins, cork, small plastic toys, and seeds like sesame seeds or chia seeds.
The buoyancy of an object determines if it will float or sink. Objects with a density less than that of the fluid they are placed in will float, while objects with greater density will sink. Additionally, the shape and size of an object can also affect whether it floats or sinks.