Which Compound Forms A Green Aqueous Solution

Which compound is formed from green water solution? ۔

1. RbCl

2. CaCl2.

3. NiCl2.

4. ZnCl2

I know the answer is 3, but why?

I know it's green, but why? Can you know

1. RbClincolor

2. CaCl2 is colorless.

3. Green NiCl2> Transition Metal.

4. ZnCl2 is colorless.

Which Compound Forms A Green Aqueous Solution

Which compound is formed from green water solution? 3
1. RbCl
2. CaCl2
3. NiCl2
4. ZnCl2
I know the answer is 3, but why?
I know it's green, but why? Can you know
1. RbClincolore
2. CaCl2 is colorless.
3. Green NiCl2> Transfer metal
4. ZnCl2 is colorless.