The answer is D, because "Animals without a backbone are invertebrates."
The second one, b synthesis reaction
Explanation:
Since, it is given that critical temperature of Argon is 150.9 K and critical pressure of Argon is 48.0 atm.
It is known that gas phase of neon occurs at 50 K. As the boiling point of Ar is more than the boiling point of neon which means that there is strong intermolecular force of attraction between argon molecules as compared to neon molecules.
This is also because argon is larger in size. As a result, induced dipole-induced dipole forces leads to more strength in Ar as compared to Ne.
Explanation:
In chemistry, a mole is the base unit of the amount of substance in a system containing elementary entities (atoms, molecules, ions, electrons), and one mole of substance corresponds to the Avogadro's constant or 
entities. The stoichiometry equation that relates the amount of substance into the measurement in moles is
,
where 
is the number of moles, 
is the amount of substance and 
is the Avogadro's constant.
Therefore,
.
Answer: cycloaddition of 1,3-butadiene and allyl anion is thermally allowed.
Explanation:
Using the frontier molecular orbital approach, we consider if the symmetry of the LUMO of the diene (1,3-cyclobutadiene) and the HOMO of the dienophile allyl anion), match each other since the diels alder reaction is a symmetry allowed process. The symmetries of these frontier molecular orbitals match each other hence the reaction is thermally allowed. It should be notes that 4+2 cycloadditions are thermally allowed although they are slow.
