Which of the following statements is true?

A: The number of electron shells in an atom is called the atomic number.
B: Boiling and melting points are chemical properties.
C: A molecule of oxygen can have atoms of carbon in it.
D: Elements are substances made of only one type of atom.

Abiologist counts the number of rabbits in a population each year and observes a decrease in population. since the coyote population has exploded, the biologist concludes that the coyote population has had a negative interaction with the rabbit population. which describes the biologist’s actions? a.) experimentationb.) inferencec.) observationd.) interacting