To determine which elements can likely form ions with multiple charges, we need to examine their electron configurations and see if they have multiple electrons in d orbitals that can be lost to form different ions.
Let's analyze the given elements' configurations:
1. Zinc ([tex]\(\text{Zn}\)[/tex]):
- Electron configuration: [tex]\([\operatorname{Ar}] 3d^{10} 4s^2\)[/tex]
- Zinc typically forms a [tex]\(+2\)[/tex] charge by losing the two 4s electrons, leading to a stable configuration with a complete [tex]\(3d^{10}\)[/tex] subshell. It does not commonly form ions with other charges.
2. Iron ([tex]\(\text{Fe}\)[/tex]):
- Electron configuration: [tex]\([\operatorname{Ar}] 3d^6 4s^2\)[/tex]
- Iron can lose both 4s electrons and one or more 3d electrons. It commonly forms [tex]\(+\mathbf{2}\)[/tex] and [tex]\(+\mathbf{3}\)[/tex] ions, making it capable of forming ions with multiple charges.
3. Sodium ([tex]\(\text{Na}\)[/tex]):
- Electron configuration: [tex]\([Ne] 3s^1\)[/tex]
- Sodium usually forms [tex]\(+1\)[/tex] ions by losing its single 3s electron. It does not typically form ions with multiple charges.
4. Cobalt ([tex]\(\text{Co}\)[/tex]):
- Electron configuration: [tex]\([\operatorname{Ar}] 3d^7 4s^2\)[/tex]
- Cobalt can lose the 4s electrons and one or more 3d electrons. It commonly forms [tex]\(+\mathbf{2}\)[/tex] and [tex]\(+\mathbf{3}\)[/tex] ions, so it can form ions with multiple charges.
5. Silver ([tex]\(\text{Ag}\)[/tex]):
- Electron configuration: [tex]\([Kr] 4d^{10} 5s^1\)[/tex]
- Silver typically forms [tex]\(+1\)[/tex] ions by losing its single 5s electron, leading to a stable [tex]\(4d^{10}\)[/tex] configuration. It does not usually form ions with other charges.
Based on this analysis, the elements that can likely form ions with multiple charges are:
- Iron (Fe)
- Cobalt (Co)
Thus, the correct selections are:
[tex]\[ 2, 4 \][/tex]
