Syllabus

• The electrons in an atom occupy the lowest available energy levels (innermost available shells).

• The electronic structure of an atom can be represented by numbers or by a diagram. For example, the electronic structure of Sodium is 2,8,1 or showing two electrons in the lowest energy level, eight in the second energy level and one in the third energy level. Students may answer questions in terms of either energy levels or shells.

• • Students should be able to represent the electronic structures of the first twenty elements of the Periodic Table in both numbers and as shell diagrams (eg to the right right).