Here's why:
* Surface tension is a measure of the cohesive forces between molecules at the surface of a liquid.
* Diethyl ether has weak intermolecular forces (van der Waals forces) due to its relatively small size and non-polar nature. This means the molecules don't stick together very strongly, resulting in a low surface tension.
For comparison, here are some other liquids with relatively low surface tensions:
* Acetone
* Hexane
* Methanol
It's important to note that surface tension is influenced by temperature. As the temperature of a liquid increases, its surface tension decreases.
