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3 years ago

Who discovered penicillin and why were chemist important in turning penicillin into a widely used life-saving medicine

Chemistry

1 answer:

Deffense [45]3 years ago

8 0

Alexander Fleming and penicillin is used to help fight gram positive bacteria and other bacterial infections

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Have people considered that aliens could possibly live without oxygen and water and we are looking in the wrong direction for a

bija089 [108]

I have never heard anyone ever say anything about aliens only living by using the same metabolistic processes as humans... But.. there may likely be another planet out there that does use oxygen, although at a different percentage from Earths. Anyways, even if we do find "other" life forms, who's to say that they're on the same level as us? Have you ever considered the fact that ants to us are like we are to other life forms out there and maybe they don't want or can't communicate with us because they see themselves as superior?

Hope that helps!

8 0

3 years ago

A flashlight battery is hooked to a toy motor, and then the battery and the connections are sprayed with a water-proof coating.

denis-greek [22]

Explanation:

Formula to calculate work done by motor is as follows.

Work done by motor = $mass \times g \times height$

where, g = gravitational constant = 10 $m/s^{2}$

Therefore, work done by motor is as follows.

Work done by motor = $1.00 kg \times 10 m/s^{2} \times 10.0 m$

= 100.0 J

Now, heat lost by water will be calculated as follows.

q = $mC \times \Delta T$

= $g \times 4.184 J/g^{o}C \times 0.024^{o}C$

= 10.0 J

Hence, heat gained by motor = heat lost by water

As, heat gained by motor = 10.0 J

So, change in energy = heat gained - work done

Therefore, change in energy will be calculated as follows.

Change in energy = heat gained - work done

= (10.0 J) - (100.0 J)

= -90.0 J

Thus, we can conclude that change in the energy of the battery contents is -90.0 J.

4 0

3 years ago

Write a nuclear reaction for the neutron-induced fission of u−235 to form xe−144 and sr−90.

rusak2 [61]

Answer:

235/92U+10n→144/54Xe+90/38Sr+2/10n

Explanation:

The nuclear reaction for the neutron-induced fission of u−235 to form xe−144 and sr−90 is represented by;

235/92U+10n→144/54Xe+90/38Sr+2/10n

In nuclear fission reactions a heavy nuclide is split into two light nuclides and is coupled by the release of energy.

3 0

3 years ago

Hydrofluoric acid and Water react to form fluoride anion and hydronium cation, like this HF(aq) + H_2O(l) rightarrow F(aq) + H_3

maksim [4K]

Answer:

Kc = 1.09x10⁻⁴

Explanation:

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To solve this question we need to find the moles of each reactant in order to solve the molar concentration of each reactan and replacing in the Kc expression. For the reaction, the Kc is:

Kc = [H₃O⁺] [F⁻] / [HF]

<em>Because Kc is defined as the ratio between concentrations of products over reactants powered to its reaction coefficient. Pure liquids as water are not taken into account in Kc expression:</em>

<em />

[H₃O⁺] = 0.110g * (1mol /19.01g) = 0.00579moles / 5.6L = 1.03x10⁻³M

[F⁻] = 0.163g * (1mol /19.0g) = 0.00858moles / 5.6L = 1.53x10⁻³M

[HF] = 1.62g * (1mol /20g) = 0.081moles / 5.6L = 0.0145M

Kc = [1.03x10⁻³M] [1.53x10⁻³M] / [0.0145M]

7 0

3 years ago

Use Avogadro's number, 6.02E23, to calculate the number

Zepler [3.9K]

Answer:

<h2>2.408 × 10²¹ is the correct answer!!</h2>

8 0

3 years ago