Question

Neutral atoms of argon, atomic number 18, have the same number of electrons as each of the following items except: K+ Ca+2 Ne Cl- S-2

Answer 1

Neutral atoms of argon, atomic number 18, have the same number of electrons as each of the following items except: Ne

Ne
1s² 2s² 2p⁶

Ar, K(+), Ca(2+), Cl(-), S(2-)
1s² 2s² 2p⁶ 3s² 3p⁶

Answer 2

Answer : The element that has no same number of electrons as of argon will be, Neon (Ne).

Explanation :

The element is, Argon

The atomic number of argon = 18

The electronic configuration of argon is,
`1s^22s^22p^63s^23p^6`

The number of electrons in argon = 18

The element is,
`K^+`

The atomic number of K (potassium) = 19

The electronic configuration of 'K' is,
`1s^22s^22p^63s^23p^64s^1`

The electronic configuration of
`K^+` is,
`1s^22s^22p^63s^23p^6`

The number of electrons in
`K^+` = 18

The element is,
`Ca^(2+)`

The atomic number of Ca (calcium) = 20

The electronic configuration of 'Ca' is,
`1s^22s^22p^63s^23p^64s^2`

The electronic configuration of
`Ca^(2+)` is,
`1s^22s^22p^63s^23p^6`

The number of electrons in
`Ca^+` = 18

The element is, Neon

The atomic number of neon= 10

The electronic configuration of neon is,
`1s^22s^22p^6`

The number of electrons in neon = 10

The element is,
`Cl^-`

The atomic number of Cl (chlorine) = 17

The electronic configuration of 'Cl' is,
`1s^22s^22p^63s^23p^5`

The electronic configuration of
`Cl^-` is,
`1s^22s^22p^63s^23p^6`

The number of electrons in
`Cl^-` = 18

The element is,
`S^(2-)`

The atomic number of S (sulfur) = 16

The electronic configuration of 'S' is,
`1s^22s^22p^63s^23p^4`

The electronic configuration of
`S^(2-)` is,
`1s^22s^22p^63s^23p^6`

The number of electrons in
`S^(2-)` = 18

Therefore, the element that has no same number of electrons as of argon will be, Neon (Ne).