instruction:
Given a scientific passage and an answer, generate a question for the given answer.
question:
Passage: Electron affinity is a measure of the energy released when an extra electron is added to an atom. Answer: electron affinity
answer:
What is the measure of the energy released when an extra electron is added to an atom?

question:
Passage: Solids have a fixed volume and a fixed shape. Liquids have a fixed volume but take the shape of their container. Gases take both the volume and the shape of their container. Answer: gases
answer:
What takes both the shape and the volume of their container?

question:
Passage: Ester molecules are polar but have no hydrogen atom attached directly to an oxygen atom. They are therefore incapable of engaging in intermolecular hydrogen bonding with one another and thus have considerably lower boiling points than their isomeric carboxylic acids counterparts. Because ester molecules can engage in hydrogen bonding with water molecules, however, esters of low molar mass are somewhat soluble in water. Borderline solubility occurs in those molecules that have three to five carbon atoms. http://catalog. flatworldknowledge. com/bookhub/reader/2547 - gob-ch15_s07_t01lists the physical properties of some common esters. Answer: hydrogen-oxygen atom
answer:
Lack of which attachment makes ester molecules incapable of intermolecular hydrogen bonding?