Question

the electron configurations of two unknown atoms are shown. based on the electron configuration of atom y, to which group in the periodic table does it belong? electron configuration atom x atom y 13 9 17 16

Explanation:

Step1: Count electrons in Atom Y

Count the electrons in each shell of Atom Y. The first shell has 2 electrons, the second has 8, and the third has 7.

Step2: Determine group number

The group number for main - group elements is determined by the number of valence electrons. Valence electrons are in the outermost shell. For Atom Y, the outermost shell (third shell) has 7 electrons. In the periodic table, elements with 7 valence electrons belong to Group 17 (halogens).

Answer:

17