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3 years ago

How is the nucleus of an oxygen -18 atom different from the nucleus of an oxygen -16 atom?

1 answer:

6 0

These are isotopes of that element. The nucleus is different because the number of neutrons differ and aren't the same. The number of protons are the same though.

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Expresar la cantidad de 620 000 con la sidra entera utilizando la potencia con base 10??

Nuetrik [128]

Respuesta:

= 6.2x10^5

5 0

3 years ago

A student researcher performed a chromatographic separation of caffeine and aspartame. The retention time for caffeine, t c , wa

KatRina [158]

Answer:

Average plate height: 67,4μm

Resolution: 3,10

Resolutin with increase N by a factor of 1,5: 3,80

Explanation:

Average plate height is the average between plate height of aspartame and caffeine.

Plate height is:

$H = \frac{L}{16(\frac{t_R}{W} )^2}$

For aspartame: $H = \frac{0,241x10^{6}um}{16(\frac{267,1s}{18,9s} )^2}$

H = 75,4 μm

For caffeine: $H = \frac{0,241x10^{6}um}{16(\frac{216,7s}{13,6s} )^2}$

H = 59,33 μm

Average plate height is:

(59,3μm + 75.4μm)/2= 67,4μm

The resolution formula is:

$R = \frac{2(t_{R2}-t_{R1})}{(w_2+w_1)}$

Replacing:

$R = \frac{2(267,1s-216,7s)}{(18,9s+13,6s)}$

R = 3,10

As resolution is proportional to the square root of the number of theoretical plates, the increasing of 1,5 in the number of theoretical plates increases the resolution by a factor of √1,5 ≈ 1,22

That means resolution would be:

R 1,5N = 3,10×√1,5= 3,80

I hope it helps!

5 0

2 years ago

Flammable and combustible materials should be stored according to

avanturin [10]

There fire label i think

5 0

3 years ago

What must models and theories do in order to remain valid

raketka [301]

There must not be credible contrary evidence to the ideas suggested by the theory.

5 0

3 years ago

A medical research lab in Europe is studying a drug's absorption in the blood. Another lab in Japan is trying to delay the

Anna11 [10]

Answer:

The correct answer is "from different social and ethnic backgrounds".

Explanation:

One of the basis of scientific research is that it is universal, which means that it can be proved and replicated in anywhere in the world. In this case, one part of the study of a drug's absorption in the blood is taking place in Europe, while other part is taking place in Japan. This means that scientific knowledge progresses due to the effort of scientists from different social and ethnic backgrounds. Actually, the most ambitious scientific researches, such as The Human Genome Project, require the simultaneous effort of multiple research institutes in the world.

7 0

2 years ago