Blue
When red litmus paper comes into contact with any alkaline substance, it turns blue. Some examples of alkaline substances are ammonia gas, milk of magnesia, baking soda and limewater.
A troposphere because that is where all the CO2 and where we live
Answer:
A- SImilar to both copper and oxygen
Explanation:
If copper and oxygen react to form copper oxide, a compound of both Copper and Oxygen, they most likely have traits from both elements, therefore its A
