Which of the following is true about elements? A. Atoms of all elements contain the same number of protons, but the number of neutrons is different for every element. B. Atoms of all elements contain neutrons, but they do not all contain protons. C. Atoms of all elements contain electrons, but they do not all contain protons. D. Atoms of all elements contain protons, but the number of protons is different for every element.
