Which of the following determines the number of valence electrons in an atom of a main group element?
A) the element's atomic number
B) the element's atomic weight
C) the element's column number
D) none of these

Question

Quizplus · Accepted Answer

The number of valence electrons in an atom of a main group element is determined by the element's column number in the periodic table. This is because elements in the same column have the same number of valence electrons. For example, all elements in column 1 (except for hydrogen) have 1 valence electron, while all elements in column 2 have 2 valence electrons, and so on. The atomic number and atomic weight are not directly related to the number of valence electrons.

Which of the Following Determines the Number of Valence Electrons