The law of conservation of mass<span> states that </span>mass<span> in an isolated system is neither created nor destroyed by chemical reactions or physical transformations.
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Answer:
MIXTURE
Explanation:
A mixture is a substance composed of a combination of other different substances. These component(s) of a mixture are physically combined, meaning that there is no chemical linkage between the individual components/constituents of a mixture.
This is the case of the gravel described in this question. The components of gravel can be separated using physical means because they are not chemically bonded to one another, hence, no chemical reactions are needed to separate different parts of gravel into pure substances. This makes gravel a MIXTURE.
Answer:
The reaction in which heat is absorbed from the surrounding is called endothermic reaction.
so
I think it's answer is 2nd option.