Question

1. how does the number of valence electrons relate to an element’s position on the periodic table?

Explanation:

• Main group elements in Group 1 have 1 valence electron, Group 2 have 2, Group 13 have 3, up to Group 18 (noble gases) which have 8 (except helium with 2).
• The period number corresponds to the principal quantum number $n$ of the valence electron shell, showing the electron's average distance from the nucleus.

Answer:

The number of valence electrons of an element is directly tied to its group (vertical column) on the periodic table:

1. For main group elements (Groups 1-2, 13-18), the number of valence electrons matches the group number (or group number minus 10 for Groups 13-18).
2. The period (horizontal row) of the element indicates the energy level where the valence electrons are located.