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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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5. Calcium carbonate decomposes at 12000 C to form carbon dioxide and calcium oxide. If 25 liters of carbon dioxide are collecte
Anika [276]

Answer:

5)0.53liters

6)1.634.6°c

Explanation:

using \:  charles \: law \\ v1 \div t1 = v2 \div t2

5) v1=25liters, t1=12000°c. v2=?, t2=250°c

v2=(250×25)/12000

v2=6250/12000

v2=0.52liters

6)v1=130,v2=85, t1=2500, t2=?

t2=(85×2500)/130

t2=212500/130

t2= 1634.6°c

5 0
3 years ago
Need ASAP will give brainlist
Leokris [45]

Answer:

A.

The answer is A :)

7 0
2 years ago
The faster the object is moving the more portential energy it has?
Mazyrski [523]

Answer:

sure

Explanation:

8 0
3 years ago
When water was added to a 4.00 gram mixture of potassium oxalate hydrate (molar mass 184.24 g/mol) and calcium hydrate shown bel
Sliva [168]

Answer:

% (COOK)2H2O = 37.826 %

Explanation:

mix: (COOK)2H2O + Ca(OH)2 → CaC2O4 + H2O

∴ mass mix = 4.00 g

∴ mass (CaC2O4)H2O = 1.20 g

∴ Mw (COOK)2H2O = 184.24 g/mol

∴ Mw (CaC2O4)H2O = 146.12 g/mol

∴ r = mol (COOK)2H2O / mol (CaC2O4)H2O = 1

  • % (COOK)2H2O = (mass (COOK)2H2O / mass Mix) × 100

⇒ mass (COOK)2H2O = (1.20 g (CaC2O4)H2O)×(mol (CaC2O4)H2O / 146.12 g (CaC2O4)H2O)×(mol (COOK)2H2O/mol (CaC2O4)H2O)×(184.24 g (COOK)2H2O/mol (COOK)2H2O)

⇒ mass (COOK)2H2O = 1.513 g

⇒ % (COOK)2H2O = ( 1.513 g / 4 g )×100

⇒ % (COOK)2H2O = 37.826 %

7 0
3 years ago
What column do these go into physical or chemical property ??
RSB [31]

Answer:

Explanation:

Chemical properties:

These are the properties which involve the chemical reaction.

For example:

Combustion, flammability, toxicity, enthalpy of formation etc are chemical properties.

Reaction with oxygen ( chemical property)

Conduction of heat ( chemical property)

Not flammable (chemical property)

Physical properties:

The property which not involve any chemical reaction it only involve the physical appearance of substance.

For example:

Density, odor, color, texture etc.

Smooth texture (physical property)

Reddish color ( chemical property)

Sink in water ( chemical property)

6 0
3 years ago
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