Answer the following question given this paragraph: 30.2 Discovery of the Parts of the Atom: Electrons and Nuclei Atoms are composed of negatively charged electrons, first proved to exist in cathode-ray-tube experiments, and a positively charged nucleus. All electrons are identical and have a charge-to-mass ratio of. Q: Atoms are composed of negatively charged electrons and a positively charged what? A:

Available options:
+ DNA segment;
+ neutron;
+ bond;
+ nucleus;
The answer is:
nucleus