Final answer:
The maximum number of electrons that an element can hold if it theoretically belongs to period 7 is 98 electrons.
Step-by-step explanation:
The maximum number of electrons that an element can hold if it theoretically belongs to period 7 is 98 electrons (d). The number of electrons that can occupy a shell is determined by the formula 2 x n², where n is the principal quantum number.
In the case of period 7, the principal quantum number is 7, so the maximum number of electrons would be 2 x 7² = 98 electrons. Each orbital can hold a maximum of 2 electrons, and the number of orbitals in any shell with principal quantum number n is equal to n².