Question 3

A neutral atom always contains an equal number of protons and electrons.

In a neutral atom, the number of protons, which carry a positive charge, is equal to the number of electrons, which carry a negative charge. This balance ensures that the overall charge of the atom is neutral.

A) Protons and electrons

This option is correct because, by definition, a neutral atom has no overall charge, which is achieved by having an equal number of positively charged protons and negatively charged electrons.

B) Protons and neutrons

This option is incorrect. While protons and neutrons are found in the nucleus of an atom, their numbers do not have to be equal. The number of protons defines the element, while the number of neutrons can vary, resulting in different isotopes.

C) Neutrons and electrons

This option is incorrect. Neutrons are neutral particles found in the nucleus, while electrons are negatively charged particles located outside the nucleus. Their numbers are not related to the neutrality of the atom.

D) Protons and alpha particles

This option is incorrect. Alpha particles consist of two protons and two neutrons, which are not the same as individual protons. The presence of alpha particles does not pertain to the neutrality of an atom, as neutral atoms do not contain alpha particles in their standard structure.

Conclusion

The correct answer is A, as a neutral atom must have an equal number of protons and electrons to maintain a balanced charge. Options B, C, and D fail to recognize the fundamental requirement for electrical neutrality in an atom, thus highlighting the essential relationship between protons and electrons in determining an atom's charge.