Question

2(c) explain why isotopes of chlorine have the same chemical properties.

question 3: electronic configuration and the periodic table
an atom of element x has the electronic configuration 2,8,7.

Explanation:

Identify the basis of chemical properties

Chemical properties of an element are determined by the number and arrangement of electrons, particularly the valence electrons in the outermost shell.

Compare electronic structures of isotopes

Isotopes of chlorine have the same number of protons and therefore the same number of electrons, resulting in the identical electronic configuration \(2, 8, 7\).

Relate electronic structure to chemical behavior

Because they have the same number of outer-shell (valence) electrons, they react in the exact same way.

Answer:

They have the same number of electrons in their outer shell (the same electronic configuration).