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Vika [28.1K]
3 years ago
14

Which of the following statements is true?

Chemistry
1 answer:
UkoKoshka [18]3 years ago
7 0
I believe A.
Calcium and potassium help with blood pressure, muscles, and bones.

For b, there is little helium in the atmosphere.
For C, the center is made of neutrons and protons, electrons are far away.
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What is paper chromatography? Calculate the Rr value of a colored dye that traveled 52 mm on a chromatography strip while the so
Karo-lina-s [1.5K]

Answer:

Paper chromatography is a basic technique of chromatography. It consist in the separation of the mixe components using a solvent.

Explanation:

Paper chromatography is a basic technique of chromatography. It consists in the separation of the mixed components using a solvent.

Paper chromatography consists of put some dot of the mix using a glass capillary into a specialized paper, generally made of cellulose, this is called a stationary phase.

Then you put this paper into a camera of glass named, chromatography camera, where previously contain a solvent. The solvent also know as a mobile phase, the type can be defined before the test and involves a study of the kind of the mix, and the compound you want to separate.

The chromatography camera has to be closed all the time during the test, and you can't move at all because the movement of the solvent can alternate the result.

Very often, the solution of the solvent is a mix of different liquid substances with different polarities.

When the stationary phase put into the camera, the solvent starts to move up over the paper, until the separation of the compounds is observable.

the Rf is a value who relates the move of the mobile phase with the move of the distance traveled by the substance tested.

To undersant the paper chromatography, you can watch the images attached.

The first is an image of the chromatography camera.

The second one is an image of a cellulose paper after the chromatography is done. You can watch the dots who indicates the traveling of the compound across the paper.

The third one can show you the evolutions of paper chromatography, from the beginning to the end.

To calculate the Rf value you have to use the equation:

Rf = distance traveled by the substance/distance traveled by the solvent/

<u>Rf = 52mm/81mm =0.64</u>

<u></u>

3 0
3 years ago
Why is an alkali metal like Sodium so reactive?
maksim [4K]
The valence electrons determine how reactive an element is, and since Sodium and other alkali metals could easily lose an electron, they become very reactive to be stable. 
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What does it mean to dilute a solution?
LenKa [72]

Answer:

Dilution is the process of decreasing the concentration of a solute in a solution, usually simply by mixing with more solvent like adding more water to the solution

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3 years ago
What gender are the blues from angry birds
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they are male

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3 years ago
SORRY THIS WAS FOR MATH which of the following terms best describes a condition in which a quantity decrease at a rate that is p
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The answer would be B
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3 years ago
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