for question 1.) i am pretty sure of answer a.)
for question 2.) the answer is most likely b.)
i would recommend waiting for a second opinion. just to be safe.
The halogen elements are the six elements in Group 17 of the periodic table. Group 17 is the second column from the right in the periodic table and contains six elements: fluorine (F), chlorine (Cl), bromine (Br), iodine (I), astatine (As), and tennessine (Ts). Astatine and tennessine are radioactive elements with very short half-lives and thus do not occur naturally.
Answer:d. law of universal gravitation
Explanation:
Pros (good):
- Inexpensive
- Can degrade the crudest oils
- Quick and minor waste is water and CO2
Cons (bad)
- Waves can carry bacteria into place they are not needed or wanted
- Germs may harm marie animals by putting excess CO2 in water
- Germs may be harder to exterminate because they are engineered