Problem 40 - Chemistry: The Central Science

Question

Identify each statement as true or false: (a) Ionization energies are always negative quantities. (b) Oxygen has a larger first ionization energy than fluorine. (c) The second ionization energy of an atom is always greater than its first ionization energy. (d) The third ionization energy is the energy needed to ionize three electrons from a neutral atom.

Step-by-Step Solution

Answer

(a) False; Ionization energies are always positive quantities. (b) False; Fluorine has a larger first ionization energy than oxygen. (c) True; The second ionization energy of an atom is always greater than its first ionization energy. (d) False; The third ionization energy refers to the energy needed to remove the third electron alone, not all three electrons together.

Step 1: (a) Ionization energies are always negative quantities.

Ionization energy is the amount of energy required to remove an electron from an atom or ion in its gaseous state. It takes energy to overcome the electrostatic attraction between the negatively charged electrons and the positively charged nucleus, so the ionization energy is a positive quantity. Thus, the statement is False.

Step 2: (b) Oxygen has a larger first ionization energy than fluorine.

When we move across a period in the periodic table from left to right, ionization energy generally increases due to a stronger electrostatic attraction between electrons and the nucleus as a result of a higher effective nuclear charge. Since fluorine is to the right of oxygen in the periodic table, fluorine has a larger first ionization energy than oxygen. Thus, the statement is False.

Step 3: (c) The second ionization energy of an atom is always greater than its first ionization energy.

The first ionization energy is the amount of energy required to remove the first electron from an atom, whereas the second ionization energy is the amount of energy required to remove the second electron from the atom after the first electron has been removed. As more electrons are removed from the atom, the effective nuclear charge experienced by the remaining electrons increases, making them more strongly attracted to the nucleus. Thus, it requires more energy to remove successive electrons. Therefore, the statement is True.

Step 4: (d) The third ionization energy is the energy needed to ionize three electrons from a neutral atom.

The third ionization energy is the amount of energy required to remove the third electron from an atom after the first and second electrons have already been removed. The statement suggests that the third ionization energy is the energy required to remove all three electrons at once, which is incorrect. The third ionization energy only corresponds to the removal of the third electron, not all three electrons together. Thus, the statement is False.