Ruby is an example of crystal with aa chemical impurity .The crystal is mainly colorless aluminium oxide, `Al_(2)O_(3)`, but occasional aluminium ions .`Al^(3+)`, are replaced by ….. .

Options

A. `Cr^(3+)` ions
B. `Co^(3+)` ions
C. `Fe^(3+)` ions
D. `Os^(3+)` ions

Answer

1

Explanation

Ruby is a red from of corundum, `Al_(2)O_(3)`, that owes its colour to traces of chromium. It is used in lasers and as a gem stone.