Given a scientific question, generate a correct answer to it.

[EX Q]: What are long chains of amino acids?
[EX A]: proteins

[EX Q]: Reef sponges typically have what type of beneficial relationships with other reef species?
[EX A]: symbiotic

[EX Q]: What is formed when each sodium atom donates its single valence electron to a chlorine atom?
[EX A]:
sodium chloride