The answer you are looking for would be a colliod. Hope this helps have a great day!!
Answer:
The dam disrupts the river wildlife and ecosystem.
Explanation:
Though it is believed that using the dam as a power generation or hydroelectric power supply generates no greenhouse gases, it, however, has many disadvantages which make it deemed not suitable or sustainable for use in the contemporary time.
Majorly, the top reason why more hydroelectric dams are not built is that "the dam disrupts the river wildlife and ecosystem."
Also, it affects the water quality and other use of water for humans such as recreational use.
There is also a possible chance of dams producing methane; a greenhouse gas through the organic materials in the water that is rotting.
Your answer is B and the element is Carbon
So what your looking for is matching isotopes. Isotopes are elements that are the same in amount of protons but different in mass meaning different number in neutrons. Because when you add the total protons and neutrons together you get your atomic mass. So this can be written as X=said element, top number above=different atomic mass, bottom number below=atomic number. Hope this help!!
Be careful because answer A has same masses but different atomic numbers so different atoms(elements)!!!