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:
What happens is,that,when a river flows into the ocean it carries some land with it. This land is made up of rocks and soil, which contains minerals. One of these minerals is Salt.
Explanation:
Single replacement because only one letter is being switched out in the reaction
B is the answer to ur question
Orbital
All atoms have the same number of electrons as protons. Negative electrons are attracted to the positive nucleus. This force of attraction keeps electrons constantly moving around the nucleus. The region where an electron is most likely to be found is called an orbital.
Here you go :)