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Solnce55 [7]
3 years ago
13

Doctors have fought infections with penicillin for over 50 years. Recently, penicillin has not worked as well as before. Which o

f the following explanations can account for this observation? A. Some bacteria are resistant to the drug. The continued use of the drug has killed all of these bacteria. B. Penicillin use has made all bacteria resistant to it. C. Some bacteria are resistant to penicillin. The continued use of the drug has killed all but these bacteria. D. Bacteria eat penicillin, so it is not effective anymore.
Chemistry
1 answer:
Lilit [14]3 years ago
5 0

C. "A" mentions that the drug killed all of the bacteria that are resistant to the drug, and that doesn't make any sense. "B" claims that all bacteria are resistant to the drug. This is not true. "D" mentions that bacteria eat the drug, which doesn't happen.

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How much heat is required to raise the temperature of 65.8 grams of water from 31.5ºC to 46.9ºC?
vodomira [7]

Answer: 1,013.32 cal × 4.18 J/cal = 4,235.68 J

Explanation:

1) Data:

Water ⇒ C = 1 cal/g°C

m = 65.8 g

Ti = 31.5°C

Tf = 36.9°C

Heat, Q = ?

2) Formula:

Q = mCΔT

3) Calculations:

Q = 65.8g × 1 cal/g°C × (46.9°C - 31.5°C) = 1,013.2 cal

4) You can convert from calories to Joules using the conversion factor:

1 cal = 4.18 J

⇒ 1,013.32 cal × 4.18 J/cal = 4,235.68 J

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pashok25 [27]
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8 0
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mamaluj [8]

False

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Carbon atoms are found in hydrocarbons, naturally occurring compound with carbon and hydrogen, but there are molecules in nature that contain beside carbon and hydrogen, oxygen and nitrogen too. In this compounds there are carbon-oxygen and carbon-nitrogen covalent bonds.

Bellow you may see the chemical structure of adrenaline, a hormon found in the human body, were the oxygen (red) and nitrogen (blue) are bonded to carbon.

Learn more about:

structure of organic compounds

brainly.com/question/14118299

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