Most elements are metals. A.
It should remain constant because of the law of conservation of mass and because the flask is sealed no mass will escape
Answer:
Spectroscopy
Explanation:
They can determine its composition based on these wavelengths. The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy
Answer:
a supposition or a system of ideas intended to explain something, especially one based on general principles independent of the thing to be explained.
(from goo gle)
A explanation for something that doesn't seem to be answered completely, usually very implausible.
Explanation:
Covalent compounds
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