The second answer is not a characteristic because compounds don’t vary from sample to sample. For example NaCl (table salt) is indistinguishable from sample to sample.
Answer:
60 mph (miles per hour)
Explanation:
0.5 hours is 1/2 of an hour, so to get the number of miles for a whole hour you multiply the miles ran by 2.
30 times 2 is 60.
Answer:
<h3>

</h3>
Explanation:
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⇒The composition , decomposition or displacement of molecules of matter during chemical change is called chemical reaction.
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Various conditions bring about these changes. The chemical reactions are represented by chemicalequation. The compounds or elements that take part in chemical reaction are called reactant. They are written at the left side of an arrow that represent a change while the compound or elements that formed after the chemical change are called product. They are written at the right side of the arrow.
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When nitrogen reacts with hydrogen to form ammonia :
Nitrogen + Hydrogen ⇒ Ammonia
N₂ + 3H₂ ⇒ 2NH₃
<u>Presentation </u><u>of </u><u>a </u><u>chemical </u><u>reaction </u><u>in </u><u>the </u><u>form </u><u>of </u><u>equation </u><u>is </u><u>called </u><u>chemical </u><u>equation </u>. <u>Chemical equation may be word equations or formula equations.</u>
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<span> d. Reduced visibility
Acid rain doesn't reduce visibility, smog does
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Explanation:
It is the heat required to change a gram of substance from a liquid to a gas.