Answer: A solution forms when the attractive _forces_ between the solute and solvent are _similar/higher_ in strength to the solvent-solvent and solute-solute attractions and are therefore able to replace them.
Explanation: Intermolecular forces between solute and solvent must be able to match or exceed the natural intramolecular forces between the solvent-solvent atoms/molecules and solute-solute atoms/molecules.
This is where the solubility law of 'like dissolves like (polar dissolves polar and likewise)' comes into play. Only polar compounds can form such attractive forces with fellow polar compounds and the same story goes for non-polar compounds.
Answer:
A and B are not the same substances.
The reason is because they do not have the same density which is a function of their masses and volumes.
For instance, for every Volume of 1mL of each substances, A has a mass of 0.97g which is different from the 0.89g of B.
9.96*10⁻²² is the answer, First you find the molar mass of gold, then you turn atoms to moles then moles to grams. There you go you're done!<span />