The most important characteristic is the polarity of the solvent and solute.
The polarity or charges of compounds will determine if a compound would dissolve in water, where compounds with opposite charges within their molecules dissolve in water.
Solubility
Whether it exerts a force on ferromagnetic objects.
The density of the substance compared to the density of the fluid it is placed in determines whether it will sink or float. If the substance is denser than the fluid, it will sink. If the substance is less dense than the fluid, it will float.
Units of measure
The density of an object is what determines whether it will sink or float in another substance. If the object's density is greater than the substance it's placed in, it will sink. If the object's density is less than the substance it's placed in, it will float.
One way to predict whether a substance will dissolve in water is to consider its molecular structure. Substances that have polar or ionic bonds are more likely to dissolve in water, as water is a polar molecule. Additionally, looking at the solubility guidelines for common types of compounds can also provide insight into whether a substance will dissolve in water.
Solubility refers to the maximum amount of a substance that can dissolve in a solvent at a given temperature and pressure, while dissolution is the process of a substance mixing uniformly with a solvent to form a solution. Solubility determines how much of a substance can dissolve in a solvent, while dissolution describes the actual process of the substance dissolving. The higher the solubility of a substance, the more easily it will dissolve in a solvent.
The distance between particles
A substance that does not dissolve is insoluble.
The chemical structure of a substance determines whether it is hydrophobic (repels water) or hydrophilic (attracts water). Hydrophobic substances have non-polar molecules that do not interact well with water, while hydrophilic substances have polar molecules that can form bonds with water molecules.
The rule of thumb that is useful for predicting whether one substance will dissolve in another is "likes dissolves likes". Similarity of substances depends on the type of bonds, intermolecular forces between solute and solvent, and if it is non-polar or polar molecule.