Which of the following ions is paramagnetic in the ground state:


Na+

Zn+2

Ti+2

Sr+2

You can look up the electron configuration at www.webelements.com. Those having unpaired electrons will be paramagnetic. I would look at Ti^+2 as a suspect.

To determine which of the given ions is paramagnetic in the ground state, we need to consider their electronic configurations.

1. Na+: The electronic configuration of sodium (Na) is 1s2 2s2 2p6 3s1. When sodium loses one electron to become Na+, its electronic configuration becomes 1s2 2s2 2p6. This configuration does not have any unpaired electrons, so it is diamagnetic, not paramagnetic.

2. Zn+2: The electronic configuration of zinc (Zn) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10. When zinc loses two electrons to become Zn+2, its electronic configuration becomes 1s2 2s2 2p6 3s2 3p6 3d10. This configuration does not have any unpaired electrons, so it is diamagnetic, not paramagnetic.

3. Ti+2: The electronic configuration of titanium (Ti) is 1s2 2s2 2p6 3s2 3p6 4s2 3d2. When titanium loses two electrons to become Ti+2, its electronic configuration becomes 1s2 2s2 2p6 3s2 3p6 3d2. This configuration has two unpaired electrons in the 3d orbital, so it is paramagnetic.

4. Sr+2: The electronic configuration of strontium (Sr) is 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2. When strontium loses two electrons to become Sr+2, its electronic configuration becomes 1s2 2s2 2p6 3s2 3p6 3d10 4p6. This configuration does not have any unpaired electrons, so it is diamagnetic, not paramagnetic.

Therefore, among the given ions, Ti+2 is paramagnetic in the ground state.

To determine which of the given ions is paramagnetic in the ground state, we need to determine if they have any unpaired electrons.

1. Na+ (Sodium ion):
Sodium (Na) has an electron configuration of 1s^22s^22p^63s^1. When it loses an electron to become Na+, the electron configuration becomes 1s^22s^22p^6, which is a completely filled electron shell. Since it has all paired electrons, Na+ is diamagnetic, not paramagnetic.

2. Zn+2 (Zinc ion):
Zinc (Zn) has an electron configuration of 1s^22s^22p^63s^23p^64s^23d^10. When it loses two electrons to become Zn+2, the electron configuration becomes 1s^22s^22p^63s^23p^64s^23d^8. Here, the 3d subshell has 8 electrons, which means it is completely filled. Since it does not have any unpaired electrons, Zn+2 is diamagnetic, not paramagnetic.

3. Ti+2 (Titanium ion):
Titanium (Ti) has an electron configuration of 1s^22s^22p^63s^23p^64s^23d^2. When it loses two electrons to become Ti+2, the electron configuration becomes 1s^22s^22p^63s^23p^6. Here, the 3d subshell becomes 1s^22s^22p^63s^23p^6, which is a completely filled electron shell. Since it has all paired electrons, Ti+2 is diamagnetic, not paramagnetic.

4. Sr+2 (Strontium ion):
Strontium (Sr) has an electron configuration of 1s^22s^22p^63s^23p^64s^23d^104p^65s^2. When it loses two electrons to become Sr+2, the electron configuration becomes 1s^22s^22p^63s^23p^64s^23d^104p^6. Here, the 4d subshell becomes 1s^22s^22p^63s^23p^64s^23d^104p^6, which is partially filled. This means Sr+2 has unpaired electrons in the 4d subshell, making it paramagnetic.

Therefore, the ion Sr+2 is paramagnetic in the ground state.