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.
Answer:
Rain forest.
Explanation: Because of how humid it is in a rain forest that humidity will bring a lot of pressure from above.
Electrons hold a negative charge, and anion refers to a negatively charged atom.
The answer is anion. Here's a way to help remember:
Cats have paws, and cations are "paws"itive (positive).
The term used to describe the rapid release of bubbles, or rapid release of a gas from a liquid or a solution is called Effervescence. The bubbling of a solution is due to the escape of a gas which may be from a chemical reaction, as in fermenting liquid, or by coming out of a solution after having been under pressure, as in a carbonated drink. For example; soda, champagne among others.
Answer:
9g
Explanation:
moles O2 = mass / Mr = 12 / 2(16.0) = 0.375
ratio O2 : NO = 5:4
moles NO produced = 0.375 * 4/5 = 0.3
mass NO = Mr * mol = (14.0+16.0) * 0.3 = 9g
