Lesson 1: Elements and Atoms

7. Self-Check Assessment

Example 1: How to calculate the number of protons, neutrons and electrons.

SC1. Calculate the number of protons, neutrons and electrons for Na and Na+

Na= 11p, 12n, 11 e. Na+= 11p, 12n, 10e.

Example 2: How to draw Bohr's energy-level diagrams.

SC2: Draw energy level diagram for Ne, and Fr

Ne has 2 energy levels, 8 valence electrons. Fr has 7 energy levels, 1 valence electron