The number of electrons that move about the nucleus of an electrically neutral atom is the same as the number of ____________________. A) protons in the nucleus.B) quarks in the nucleus.C) protons + neutrons in the nucleus.D) neutrons in the nucleus.E) None of these.

To answer this question, we need to understand the concept of atomic structure. An atom consists of a positively charged nucleus at the center, which contains protons and neutrons, and negatively charged electrons that move around the nucleus.

Since the atom is electrically neutral, it means that the positive charge from the protons in the nucleus is balanced by the negative charge from the electrons. The number of electrons and protons must be equal to maintain this balance.

Therefore, the correct answer is A) protons in the nucleus. The number of electrons that move about the nucleus of an electrically neutral atom is the same as the number of protons in the nucleus.