Answer:
Part A. F + e⁻ → F⁻
Part B. -820 kJ
Part C. -5.45x10⁻²² kJ
Explanation:
Part A
The fluoride anion is formed when fluorine accepts an electron:
F + e⁻ → F⁻
Part B
The electron affinity is the energy necessary for the atom to accept 1 electron, which is exothermic, so it's negative. The total energy q is the electron affinity multiplied by the number of moles:
q = -328 kJ/mol * 2.5 mol
q = -820 kJ
Part C
By the Avogadros' number
1 mol --------- 6.02x10²³ atoms
x --------- 1 atom
By a simple direct three rule:
x = 1.66x10⁻²⁴ mol
So, the energy for 1 atom is:
q = -328 kJ/mol * 1.66x10⁻²⁴ mol
q = -5.45x10⁻²² kJ