Riddle: What is black when you buy it, red when you use it, and gray when you throw it away?
Did you immediately get the answer or do you need some help? If you need some assistance, keep on reading our explanation!
The material that is asked in the question is something that changes and transforms. It is not stable… Like most of us who are locked in our houses due to Covid-19.
Anyways… This mysterious material changes colors. Black to red to gray… Could it be:
Yes, it could!
Because it starts off black – a carbon-rich block of fuel. Then it turns red – releasing energy in the form of light and heat. Finally, it turns gray – ashy and depleted of all usefulness.