Question

Which of the following produces green colour in fireworks?

• A. $Cr$
• B. $Fe$
• C. $K$
• D. $Na$

Answer 1

The correct option is A $Cr$

Ammonium dichromate on thermal decomposition yields $C{r}_2{O}_3,$ nitrogen gas and water.

$(N{H}_4{)}_{2}C{r}_2{O}_7\to C{r}_2{O}_3+N_2+4H_{2}O$
Chromium(III) oxide, $C{r}_2{O}_3,$ is green in colour.