Physical changes are when things get changed without altering chemical consistencies, which is melting solid butter into liquid one, or boiling water. Chemical changes are things such as caramelizing sugar when making sweets, or when carbon dioxide is created and released when baking bread.
Answer:


Explanation:
Hello,
Based on the given undergoing chemical reaction is is rewritten below:

By stoichiometry we find the minimum mass of H2SO4 (in g) as shown below:

Moreover, mass of H2 gas (in g) would be produced by the complete reaction of the aluminum block turns out:

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Answer:
The answer is C
Explanation:
This is the answer because it is the only way that it is okay to split in half.
Noble Gas. Metals have 1 or 2 Valence Electrons. Halogens have 7 Valence Electrons. Semi-Metals can have different amounts.