Question detail

Which of the following statements about ionisation energy is correct?

Try the question, check the answer, then read the explanation to understand the curriculum point.

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At a glance

MCQ

Type

practice

Style

Topic

Atomic structure

Question

A. Ionisation energy decreases down a group.
B. Ionisation energy increases down a group.
C. Ionisation energy is the same for all elements.
D. Ionisation energy is only relevant for metals.

Answer

Ionisation energy decreases down a group.

Explanation

The evidence indicates that as you move down a group, the outer electrons are further from the nucleus and experience greater shielding from inner electrons. This results in a decrease in ionisation energy. The implication is that it becomes easier to remove an outer electron as you go down a group. Thus, the conclusion is that ionisation energy decreases down a group due to increased distance and shielding.

Common mistake

Misunderstanding Ionisation Energy Trends

Students often confuse the trends in first and successive ionisation energies, failing to recognize that successive ionisation energies increase due to the removal of electrons from an increasingly positive ion.

To fix this, students should focus on understanding that as electrons are removed, the remaining electrons experience a greater effective nuclear charge, leading to higher ionisation energies. Reviewing the concepts of electron shielding and effective nuclear charge can also help clarify these trends.

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