Chemistry

Question Analysis
This question tests the student's ability to use shorthand notation to represent the electron configuration of an element.

Key Concept Explanation
Shorthand notation uses the symbol of a noble gas (in square brackets) to represent the filled inner electron configuration, followed by the valence shell configuration.

Step-by-step Solution
1. Identify the noble gas before sodium: Neon (Ne, atomic number 10).
2. Write the shorthand notation: [Ne] for the filled inner shells.
3. Add the valence shell c...