Answer:
i think it's the last option but i might be wrong
Answer:

Explanation:
An element only has <u>one</u> type of atom and cannot be broken down by chemical means.
Let's analyze the answer choices.
1. This has two types of atoms, so it cannot be an element. It has more than one type of atom.
2. This has two types of atoms that are bonded together. It cannot be an element because there is more than one type of atom and the bonds can be broken.
3. This has one type of atoms, so it is an element.
Therefore the best answer choice is 3.
Sediment - rock that has formed from sediment deposited by water or air
Deposition - the geological process in which sediments, soil and rocks are added to a landform or land mass
Environment - the surroundings or conditions in which a person, animal, or plant lives or operates