Environmental Hazards are usually any chemicals that donot naturally occur to exist anywhere and are usually made in the fields of industry or experimental sciences
So if you happen for example to throw a bit of mercury in some river while being in a school trip then this is an environmental hazard created by humans
Answer:
A and D are the answers
Explanation:
the other two don't make sense
Yes a compound a thing that is composed of two or more separate elements; a mixture.
