Detailed Instructions: Given a scientific passage and an answer, generate a question for the given answer.
Q: Passage: Atoms form covalent bonds by sharing valence electrons. The valence electrons are located in atomic orbitals. However, when a bond forms, the structure of the atomic orbitals changes. In this lesson, we will see how the atomic orbitals interact to share valence electrons and form different types of covalent bonds. Answer: covalent bonds
A:
What do atoms form by sharing valence electrons?