For an atom to be neutrally charged, which condition must be met?

For an atom to be neutrally charged, the key condition that must be met is that the number of protons equals the number of electrons. Protons, which are positively charged particles found in the nucleus of an atom, must be balanced by an equal number of negatively charged electrons that orbit the nucleus. When these two quantities are equal, the positive and negative charges cancel each other out, resulting in a neutral atom.

If an atom has more protons than electrons, it will be positively charged, forming a cation. Conversely, if it has more electrons than protons, it will be negatively charged, forming an anion. The equal quantity of protons and electrons is essential for maintaining electrical neutrality in an atom. This understanding is fundamental in the study of atomic structure and charge balance.

The other conditions mentioned do not directly relate to the neutral charge of an atom. The equality of neutrons to protons does not affect charge; it simply relates to isotopes. A zero mass number would imply an absence of particles, which is not feasible for an atom. Thus, the equality of protons and electrons is the only condition that ensures electrical neutrality.