What is the maximum number of electrons that can occupy the fourth main shell?

The maximum number of electrons that can occupy a main shell is determined by the formula 2n², where n is the principal quantum number corresponding to the shell number. For the fourth main shell, n is 4.

By applying the formula:

2n² = 2(4)² = 2(16) = 32.

This calculation shows that the fourth main shell can accommodate a maximum of 32 electrons.

This concept is grounded in the structure of electron shells and how electrons fill these shells according to quantum mechanics. Lower-numbered shells can hold fewer electrons due to their proximity to the nucleus and the effective nuclear charge they experience, but as one moves to higher shells, the capacity for additional electrons increases, especially for the fourth shell and beyond.

Overall, recognizing this formula allows for the comprehension of electron arrangement in atoms, which is foundational in chemistry for understanding elemental properties and behaviors in reactions.