Question

chemistry resources
the first ionization energy (ie₁) of an atom is the amount of energy
required to remove the atoms first valence electron. while the first ionization
energy of an individual atom is often expressed in electron volts (ev), the first
ionization energy of a substance is typically expressed in kilojoules per mole
(kj/mol). the chemical equation below represents the first ionization of
potassium.
k (g) → k⁺ (g) + e⁻ ie₁ = 419 kj/mol
select the true statements.
when one potassium atom is supplied with 419 kj of energy, it
loses one electron.
the ie₁ of a potassium atom is the amount of energy needed to
remove one of potassiums core electrons.
it takes 419 kj of energy to remove one mole of electrons from
one mole of potassium ions (k⁺).
when an electron is removed from a potassium atom, it forms a
positively - charged ion.

Explanation:

• Ionization energy is the energy required to remove an electron. For potassium, \(IE_1 = 419\space kJ/mol\) means \(419\space kJ\) is needed to remove one mole of electrons from one mole of potassium atoms (\(K(g)\)). When an electron is removed from \(K(g)\), \(K^{+}(g)\) (a positively - charged ion) is formed. Core electrons are not removed in the first ionization (valence electron is removed).
• The first ionization energy is for removing a valence electron, not a core electron. And the reaction \(K(g)\to K^{+}(g)+e^{-}\) shows that when electrons are removed from \(K\) (not \(K^{+}\)), \(K^{+}\) is formed.

Answer:

• When one potassium atom is supplied with \(419\space kJ\) of energy, it loses one electron. (False, it's per mole. \(419\space kJ\) is for one mole of \(K\) atoms to lose one mole of electrons).
• The \(IE_1\) of a potassium atom is the amount of energy needed to remove one of potassium's core electrons. (False, it's for valence electron).
• It takes \(419\space kJ\) of energy to remove one mole of electrons from one mole of potassium ions (\(K^{+}\)). (False, the reaction \(K(g)\to K^{+}(g)+e^{-}\) shows the energy is for \(K\) to \(K^{+}\)).
• When an electron is removed from a potassium atom, it forms a positively - charged ion. (True, as \(K(g)\to K^{+}(g)+e^{-}\))