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Brilliant_brown [7]
2 years ago
8

Which element makes up most of the air we breathe.

Chemistry
1 answer:
labwork [276]2 years ago
7 0
Gasses the most abundant natural occurring gas is nitrogen which makes up 78% of the air.
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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
On what is the geologic time scale based?
nekit [7.7K]

Answer: Either A or D

Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils, and estimated the time scales based on studying rates of various kinds of weathering, erosion, sedimentation, and lithification.

5 0
3 years ago
Read 2 more answers
If I have 7.5 L of a gas in a piston at a pressure of 1.75 atm and compress the gas until its volume is 3.7 L, what will the new
Sergio [31]

Answer:

3.55atm

Explanation:

We will apply Boyle's law formula in solving this problem.

P1V1 = P2V2

And with values given in the question

P1=initial pressure of gas = 1.75atm

V1=initial volume of gas =7.5L

P2=final pressure of gas inside new piston in atm

V2=final volume of gas = 3.7L

We need to find the final pressure

From the equation, P1V1 = P2V2,

We make P2 subject

P2 = (P1V1) / V2

P2 = (1.75×7.5)/3.7

P2=3.55atm

Therefore, the new pressure inside the piston is 3.55atm

7 0
3 years ago
H-1
bonufazy [111]
Answer = B = Neutrons and Mass Number

Isotopes 
are defined as those atoms which have same atomic number but different atomic masses.

Atomic mass is basically the number of protons and neutrons present in an atom.

Atomic number is the number of protons present in an atom.

So, in isotopes the number of protons are same but the number of neutrons vary due to which atomic masses also vary.
In given three isotopes, all have same number of protons but different number of neutrons.
i.e.
H-1 = 1 P + 0 N = 1 u (Proton)
H-2 = 1 P + 1 N = 2 u (Deuterium)
H-3 = 1 P + 2 N = 3 u (Tritium)

Hence, it is clear that the number after H shows a change in number of neutrons and mass number.

7 0
4 years ago
Read 2 more answers
If a wave has a frequency of 2.85x10^10 its wavelength is ?
Ede4ka [16]

Answer:

tepo jds fnsdmv dfjv dfj pvjdf ifjv dfjv sdijghdfuiExplanation:

3 0
4 years ago
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