MCQ
An ion has $18$ electrons in the outermost shell, it is
- ✓$C{u^ + }$
- B$T{h^{4 + }}$
- C$C{s^ + }$
- D${K^ + }$
✓
Answer
Correct option: A.
$C{u^ + }$
a
Atomic number of copper $Cu$ is $2 9 .$
Atomic number of copper $Cu$ is $2 9 .$
Electronic configuration of copper $=2,8,18,1$
When copper loses one electron then it becomes a positive ion that is $Cu^+$.
No of electrons in ionic $Cu^+\,=$ atomic no. of copper $-$ no. of electrons lost
$=29-1=28$
Therefore electronic configuration of copper ion $Cu^+\, 2,8,18.$
This means that $Cu^+$ has $18$ electrons in its outermost shell.
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