The answer is (2) Copper. Because copper is consist of atom. If it is decomposed, the atom will be changed. While chemical change is just the break down and form of chemical bonds between atoms.
H20 is a simple form of nice
Answer:

Explanation:
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In this case, since the decomposition of potassium chlorate is:

We can see a 2:3 mole ratio between potassium chlorate and oxygen (molar mass 32.0 g/mol), thus, via stoichiometry, we compute the mass of oxygen that are produced by the decomposition of 2.50 moles of this reactant:

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Answer:
1 mole of gas = 22.4L
2.5 moles of gas takes up = ( 22.4 L/ 1 mole ) x 2.5 mole
= 56 L
Explanation:
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