Question

choose some examples of the explanatory power of the quantum - mechanical model. check all that apply. it explains the number of isotopes each atom has. it explains how many electrons the atoms gain or lose. it explains the total number of electrons each atom has. it explains periodic trends in ionization energy. it explains whether the atoms are likely to lose or gain protons and neutrons. it explains periodic trends in the nuclear properties of the atoms. it explains the chemical properties of the atoms, such as their tendency to gain or lose electrons.

Explanation:

• The quantum - mechanical model is mainly concerned with the behavior and distribution of electrons in atoms.
• It helps in understanding periodic trends related to electrons. For example, ionization energy (the energy required to remove an electron from an atom) has periodic trends that can be explained by the quantum - mechanical model as it relates to electron configurations.
• The chemical properties of atoms, such as their tendency to gain or lose electrons, are also related to electron configurations which are described by the quantum - mechanical model.

• The number of isotopes is related to the number of neutrons in an atom and is not explained by the quantum - mechanical model of electrons.
• The total number of electrons in an atom is determined by the atomic number (proton number) and is a basic atomic property, not specifically explained by the quantum - mechanical model's explanatory power in the context of its unique contributions (like periodic trends and chemical behavior).
• Atoms do not gain or lose protons (except in nuclear reactions, not related to quantum - mechanical model of electrons) and neutrons are not directly related to the quantum - mechanical model of electron behavior. Nuclear properties trends are not explained by the quantum - mechanical model of electrons.

Answer:

It explains periodic trends in ionization energy.
It explains the chemical properties of the atoms, such as their tendency to gain or lose electrons.