Answer:
589.8 kJ/mol
Step-by-step explanation:
Let's consider the process in which the most loosely bound electron from each atom in a mole atom of gaseous calcium is removed.
Ca(g) + Energy ⇒ Ca¹⁺(g) + 1 e⁻
The energy involved in this process is known as First Ionization Energy. The First Ionization Energy for calcium is 589.8 kJ/mol.