The [tex]kr[/tex] symbols would be included in the noble gas notation for an element that had valence electrons in the 5s subshell.
So, option first is correct one.
Since, [tex]kr[/tex] is placed at 4th period and 18th group and element that had valence electrons in the 5s subshell belong to 5th period or either 1st or 2nd group.
What is noble gas family?
- The elements in the periodic table having complete subshell is called noble gas family.
- The properties of noble gas are odorless, colorless, low chemical reactivity etc
- The most natural occurring noble gas are [tex]helium[/tex], [tex]neon[/tex], [tex]argon[/tex], [tex]xenon[/tex],[tex]krypton[/tex] and radioactive [tex]radon[/tex].
To learn more about noble gas,
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