For the first question nail rusting is not an example of physical change
<span>The stopper should be held until it can be safely re-inserted. Placing it on any other type of surface or table could run the risk of cross-contamination. This could cause issues with the reagent when the stopper is replaced.</span>
Answer:
London dispersion forces
Explanation:
Intermolecular forces are the forces that facilitate interaction between solute and solvent molecules and thereby impact their solubility. These forces are broadly classified into four types arranged below from the strongest to the weakest:
1) Ionic > 2) Hydrogen bonding >3) Dipole-dipole >4) London dispersion
The hydrocarbons n-pentane and n--hexane are non-polar molecules. Therefore the only type of interaction that exists between them when forming a homogeneous solution are the weak london dispersion forces.