Good chemistry question

How did scientists figure out that valence electrons existed?

Explanation:

Would Valence be a good baby name?

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation:

14,16 18 reacts with group