Question

write the complete ground - state electron configuration of be²⁺. for multi - digit superscripts or coefficients, use each number in succession

Explanation:

Step1: Determine the atomic number of Be

The atomic number of Be (beryllium) is \( Z = 4 \).

Step2: Analyze the ion \( Be^{2 + } \)

For \( Be^{2 + } \), the number of electrons \( N_e=Z - 2\). Since \( Z = 4 \), \( N_e=4 - 2=2 \).

Step3: Write the electron configuration

The electron configuration of an atom/ion with \( N_e = 2 \) follows the Aufbau principle. The first shell (\( n = 1 \)) has the \( 1s \) sub - shell. The maximum number of electrons in the \( 1s \) sub - shell is \( 2 \). So the electron configuration is \( 1s^{2} \).

Answer:

\( 1s^{2} \)