The atomic number of carbon is six, which means that a carbon atom has six protons. Carbon has three naturally occurring isotopes: carbon-12, carbon-13, and carbon-14. Which of these statements are true about carbon and its isotopes? Select all that apply. A. All carbon atoms have six neutrons.
B. All carbon atoms have six protons and six electrons.
C. Atoms of all carbon isotopes have either more than 6 electrons or fewer than 6 electrons.
D. Atoms of some naturally occurring carbon isotopes may have six neutrons.
E. Atoms of some naturally occurring carbon isotopes may have twelve neutrons.

The hershey and chase experiments involved the preparation of two different types of radioactively labeled phage. which of the following best explains why two preparations were required? a. the bacteriophage used in the experiments was a t2 phage. b. it was necessary that each of the two phage components, dna and protein, be identifiable upon recovery at the end of the experiment. c. each scientist had his own method for labeling phage, so each conducted the same experiment using a different isotope. d. establishing the identity of the genetic material required observation of two phage generations.