Final answer:
The first energy level can hold a maximum of 2 electrons, since it consists of one s orbital which accommodates two electrons with opposite spins.
Step-by-step explanation:
The first energy level of an atom, also known as the K shell, can hold a maximum of 2 electrons. This is because the first energy level consists of a single s orbital (1s), and according to the Pauli exclusion principle, each orbital can hold a maximum of two electrons with opposite spins. The general formula for the maximum number of electrons that a shell can accommodate is 2n², where 'n' represents the energy level. For the first energy level (n=1), the calculation is 2(1²) = 2, confirming that only two electrons can occupy the first energy level.