Convert 0.820 grams to milligrams. Enter your answer using standard scientific or "e" notation and the correct number of significant figures (for example, 105 = 1.05e2).
I got the answer 820 milligrams, 8.2e2. but I was told that I was wrong. Please help.
I got the answer 820 milligrams, 8.2e2. but I was told that I was wrong. Please help.
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The reason its wrong is because 0.820 has 3 sig figs and your answer only has 2.
The zero after the 2 is a sig fig because it shows that when 0.820mg was measure, it was exactly 0.820 and not 0.821 or 0.826. If you were given 0.82mg, you would not know if it was exactly 0.82mg or if the answer was rounded (.821, .822, .823, and .824 would all round to 0.82) By putting down 0.820, you know that it was 820mg and not 821-824mg.
If you were given 0.8200 you would have 4 sig figs because that would mean you had 820.0 mg while 3 sigs figs(820mg) would only guarantee accuracy to on the mg level, 820.0 guarantees it to the tenth of a mg level.
The zero after the 2 is a sig fig because it shows that when 0.820mg was measure, it was exactly 0.820 and not 0.821 or 0.826. If you were given 0.82mg, you would not know if it was exactly 0.82mg or if the answer was rounded (.821, .822, .823, and .824 would all round to 0.82) By putting down 0.820, you know that it was 820mg and not 821-824mg.
If you were given 0.8200 you would have 4 sig figs because that would mean you had 820.0 mg while 3 sigs figs(820mg) would only guarantee accuracy to on the mg level, 820.0 guarantees it to the tenth of a mg level.
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yes 820 mg is correct so it should be 8.2e2..