Answer: 2. cannot be an element.
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper 
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: methane 

Thus as it can be decomposed into its constituent elements, it is a compound.
Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present.
Thus methane cannot be an element.
It will be:
b. Alkyne* series
* You have done a spelling mistake here. It will be "Alkene" not "Alkyne".
Answer:without predators, to keep prey from producing too many and over eating, the ecosystem suffers as there isn’t enough for the prey themselves to eat.
Explanation:
Answer:
2482.4177376
Explanation:
1: 5.82 760 times 425.976
2: You will find the answer that is 2482.4177376
<em><u>Hope this helps.</u></em>
Electron
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