Final answer:
The most accurate statement about ionization energy is that metals have lower ionization energies than nonmetals, ionization energy decreases down a group, and increases left to right across a period. Noble gases have high ionization energies due to their stable electron configurations.
Step-by-step explanation:
The most accurate statement regarding ionization energy is that metals tend to have lower ionization energies than nonmetals, it tends to decrease as you move down a group, and it tends to increase as you move across a period from left to right on the periodic table. Ionization energy refers to the energy required to remove an electron from an atom, and it is affected by various factors such as atomic radius, electron shielding, and nuclear charge.
As you move down a group on the periodic table, the atomic size increases, placing the valence electrons further away from the nucleus, which makes them easier to remove due to less electrostatic attraction to the nucleus, thus decreasing ionization energy. When moving from left to right across a period, the atomic size decreases, the effective nuclear charge increases, and as a result, the valence electrons are held more tightly by the nucleus, leading to an increase in ionization energy.
Therefore, the noble gases located at the far right of the periodic table tend to have the highest ionization energies, not the lowest. This is due to their stable electron configurations, making them less inclined to lose electrons. Hence, considering all the given options, A is the most accurate as it states that 'Metals tend to have lower ionization energies than nonmetals.'