Final answer:
Nigel was unable to make the longest straw work due to the cohesive forces of water not allowing for water molecules to be removed from small pores, even when gravity is applied.
Step-by-step explanation:
In this case, Nigel was not able to make the longest straw work because of the cohesive forces of water.
The cohesive forces of water make it difficult for water molecules to be removed from small pores, even when gravity is applied.
This is why Nigel was unable to suck the water out of the longest straw, as gravity was not strong enough to overcome the cohesive forces of water.