Given a scientific passage and an answer, generate a question for the given answer.

Passage: Sulfate minerals contain sulfur atoms bonded to oxygen atoms. Like halides, they can form in places where salt water evaporates. Many minerals belong in the sulfate group, but there are only a few common sulfate minerals. Gypsum is a common sulfate mineral that contains calcium, sulfate, and water. Gypsum is found in various forms. For example, it can be pink and look like it has flower petals. However, it can also grow into very large white crystals. Gypsum crystals that are 11 meters long have been found. That is about as long as a school bus! Gypsum also forms at the Mammoth Hot Springs in Yellowstone National Park, shown in Figure below . Answer: oxygen and sulfur
What two types of atoms bond to form sulfate minerals?

Passage: Biotic factors are all of the living or once-living aspects of the environment. They include all the organisms that live there as well as the remains of dead organisms. Answer: biotic factors
What are all of the living or once-living aspects of the environment called?

Passage: An ionic bond is the force of attraction that holds together oppositely charged ions. Ionic bonds form crystals instead of molecules. Table salt contains ionic bonds. Answer: ionic bond
What term means the force of attraction that holds together oppositely charged ions?