Given a scientific passage and an answer, generate a question for the given answer.
--------
Question: Passage: They are ectothermic , meaning their temperature depends on the temperature of their environment. Ectothermic animals are cold-blooded in that they cannot raise their body temperature on their own. This is unlike humans, whose temperature is controlled from inside the body. Answer: ectothermic

Answer: What is the term for animals that cannot raise their body temperature on their own?

Question: Passage: Many samples have a lot of variation in measurements. Variation can be described with a statistic called the range. The range is the total spread of values in a sample. It is calculated by subtracting the smallest value from the largest value. Answer: range

Answer: What term is used to describe the total spread of values in a sample?

Question: Passage: Ions are highly reactive, especially as gases. They usually react with ions of opposite charge to form neutral compounds. For example, positive sodium ions and negative chloride ions react to form the neutral compound sodium chloride, commonly known as table salt. This occurs because oppositely charged ions attract each other. Ions with the same charge, on the other hand, repel each other. Ions are also deflected by a magnetic field, as you saw in the opening image of the northern lights. Answer: repel each other

Answer:
What do ions of the same charge do?