The periods inside the Periodic Table is B. a horizontal row, and is numbered 1 through 7
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With a physical change you can actually see it change like ice turning into water, then with a chemical change you can't see it change, although within the molecules themselves they change which makes that possible.
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Answer:
option c
Explanation:
as catalyst increases the reaction while activation energy is inversely proportional to rate of reaction, so option c is correct
When a meteroid goes into the atmosphere the friction starts slowing it down and generating heat.