To determine which element among the given options is most likely to form ions with a 2+ charge, we need to look at their positions in the periodic table and their typical ionization behaviors.
1. Cs (Cesium):
- Cesium is in Group 1 of the periodic table.
- Group 1 elements typically lose one electron to form 1+ ions.
- Therefore, Cs tends to form a Cs⁺ ion.
2. Cl (Chlorine):
- Chlorine is in Group 17 of the periodic table.
- Group 17 elements typically gain one electron to form 1- ions.
- Therefore, Cl tends to form a Cl⁻ ion.
3. O (Oxygen):
- Oxygen is in Group 16 of the periodic table.
- Group 16 elements typically gain two electrons to form 2- ions.
- Therefore, O tends to form an O²⁻ ion.
4. Te (Tellurium):
- Tellurium is also in Group 16 of the periodic table, like oxygen.
- Group 16 elements typically gain two electrons to form 2- ions.
- Therefore, Te tends to form a Te²⁻ ion.
5. Ba (Barium):
- Barium is in Group 2 of the periodic table.
- Group 2 elements typically lose two electrons to form 2+ ions.
- Therefore, Ba tends to form a Ba²⁺ ion.
Given these points, Barium (Ba) is the element most likely to form ions with a 2+ charge.
Thus, the element most likely to form ions with a 2+ charge is Ba (Barium).
So the answer is:
5. Ba
