Electronic Structure of the Atom ·An atom has a dense, positively charged electron density nucleus surrounded by a cloud of electrons. The electron density is distance distance from the nucleus highest at the nucleus and drops off nucleus exponentially with increasing distance from the nucleus in any direction. 2013 Pearson Education,Inc. Chapter 1 3© 2013 Pearson Education, Inc. Chapter 1 3 Electronic Structure of the Atom • An atom has a dense, positively charged nucleus surrounded by a cloud of electrons. • The electron density is highest at the nucleus and drops off exponentially with increasing distance from the nucleus in any direction