B I’m pretty sure. (Sorry if I wrong-)
<u>Answer:</u>
D<u>ispersion force :</u> is the weakest intermolecular force. The London dispersion force is a temporary attractive force that results when the electrons in two adjacent atoms occupy positions that make form temporary dipoles. This force is also called an induced dipole-induced dipole attraction because one molecule induce dipole in other molecule. London forces are the attractive forces that cause non polar substances to condense to liquids and to freeze into solids when the temperature is lowered sufficiently.
<u>Molecular size
:</u>
•Larger and heavier atoms and molecules exhibit stronger dispersion forces than lighter and smaller ones.
•In a larger atom or molecule, the valence electrons are, farther from the nuclei than in a smaller atom or molecule. They are less tightly bounded and can more easily form temporary dipoles.
<u>Molecular shape:
</u>
•At room temperature, neopentane (C5H12) is a gas whereas n-pentane (C5H12) is a liquid.
•London dispersion forces between n-pentane molecules are stronger than those between neopentane molecules even though both molecules are nonpolar and have the same molecular weight.
•The somewhat cylindrical shape of n-pentane molecules allows them to come in contact with each other more effectively than the somewhat spherical neopentane molecules.
so here
,
2 > 3 > 1 > 4 > 5 > 6
1st have more dispersion force because it is n heptane present in liquid form.
6th have lowest force because it is present in gaseous form.
There are two molecular orbitals in the CH2O or formaldehyde. These are designated by the two types of bonding involved. The first is the sigma bonding. It is the head-on overlap of electrons of the C and H atoms. The second molecular orbital is formed from the pi orbital bonding. This is a sideway overlap of electrons between C-O bonding.
Temperature means, in this context, movement.
Condensation can be explained by the reduction of temperature of the system. This effect make possible the cohesion forces increases. In other words, the result is coalescence by attractive forces.
