If the colours of salts of transition elements are due to the presence of unpaired electrons in the transition metal ions, which of the following ions will be colourless in aqueous solution

Options

A. `Ti^(3+)`
B. `Ti^(4+)`
C. `Fr^(2+)`
D. `Fr^(3+)`

Answer

B

Explanation

`Ti^(+4)to 3d^(0) 4s^(0)therefore ` no unpaired `e ^(-).`