The ionisation energy diagnostic instrument: a two-tier multiple-choice instrument to determine high school students’ understanding of ionisation energy

Abstract

The topic of ionisation energy is important as the concepts involved provide the foundation for the understanding of atomic structure, periodic trends and energetics of reactions. Previous research has shown that A-level (high school) students in the United Kingdom had difficulty understanding the concepts involved in ionisation energy. This paper describes the development and administration of a two-tier, multiple-choice instrument on ionisation energy, the Ionisation Energy Diagnostic Instrument, to determine if A-level students (Grade 11 and 12, 17 to 18 years old) in Singapore have similar alternative conceptions to those of their counterparts in the United Kingdom, as well as explore their understanding of the trend of ionisation energies across Period 3. The items in such instruments are specifically designed to identify alternative conceptions and misunderstandings in a limited and clearly defined content area. The results showed that students in Singapore applied the same octet rule framework and conservation of force thinking to explain the factors influencing ionisation energy as the students in the United Kingdom. In addition to the above alternative frameworks, many students in Singapore also resorted to relation-based reasoning to explain the trend of ionisation energies across Period 3 elements. [Chem. Educ. Res. Pract., 2005, 6 (4), 180-197]