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3 years ago

How do scientists know that the universe is expanding?

2 answers:

7 0

It is known that the elements captivate and emit specific wavelengths of light, that is, the part of the electromagnetic spectrum. By examining the wavelengths of light discharged by an object in space, one can attain an ample amount of information. The astronomers studied the variation in the position of lines in the spectrum from a star, this can predict the distance of the star, that is, and whether it is moving away or towards us, and how quickly it is moving.

While studying the radiation discharged by the galaxies or the distant stars, the scientists witnessed the shifting of emission spectra towards the red region of the electromagnetic spectrum, that is, the witnessed wavelengths are longer than anticipated.

There is something, which is responsible for the wavelength of the radiation to stretch. However, in spite of a real variation in the wavelength, this procedure was something identical to the Doppler Effect.

DanielleElmas [232]3 years ago

4 0

Galaxies are moving away from us and the farther away a galaxy is the faster it is moving away from us. The galaxies seem to be receding from us because the entire universe is getting larger.

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The reaction of nitrogen gas and oxygen gas to form nitrogen monoxide gas is shown below. If the measured concentrations of all

Anettt [7]

Answer:

The forward reaction is occurring at a faster rate than the reverse reaction.

Explanation:

Reaction quotient (Q) of the given reaction is -

$Q=\frac{[NO]^{2}}{[N_{2}][O_{2}]}$

where [NO], $[N_{2}]$ and $[O_{2}]$ represents concentrations of respective species at a certain time.

Here $[N_{2}]$ = 0.80 M, $[O_{2}]$ = 0.050 M and [NO] = 0.10 M

So, $Q=\frac{(0.10)^{2}}{(0.80)\times (0.050)}=2$

Hence $Q> K$

It means that forward reaction is faster than reverse reaction at that point. Because then only concentration of NO is higher than concentrations of $[N_{2}]$ and $[O_{2}]$ which makes Q higher than K.

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3 years ago

Air, with an initial absolute humidity of 0.016 kg water per kg dry air, is to be dehumidified for a drying process by an air co

amid [387]

Answer:

(a) The proportion of dry air bypassing the unit is 14.3%.

(b) The mass of water removed is 1.2 kg per 100 kg of dry air.

Explanation:

We can express the proportion of air that goes trough the air conditioning unit as $p_{d}$ and the proportion of air that is by-passed as $p_{bp}$ , being $p_{d}+p_{bp}=1$ .

The amount of water that goes into the drier inlet has to be 0.004 kg/kg, and can be expressed as:

$0.004 = 0.016*p_{bp}+ 0.002*p_{d}$

Replacing the first equation in the second one we have

$0.004 = 0.016*(1-p_{d})+ 0.002*p_{d}=0.016-0.016*p_{d}+0.002*p_{d}\\0.004 - 0.016 = (-0.016+0.002)*p_{d}\\-0.012 = -0.014*p_{d}\\p_{d}=\frac{-0.012}{-0.014}=0.857\\\\p_{bp}=1-p_{d}=1-0.857=0.143$

(b) Of every kg of dry air feed, 85.7% goes in to the air conditioning unit.

It takes (0.016-0.002)=0.014 kg water per kg dry air feeded.

The water removed of every 100 kg of dry air is

$100 kgDA*0.857*0.014 kgW/kgDA= 1.1998 \approx 1.2 kgW$

It can also be calculated as the difference in humiditiy between the inlet and the outlet: (0.016-0.004=0.012 kgW/kDA) and multypling by the total amount of feed (100 kgDA).

100 * 0.012 = 1.2 kgW

7 0

3 years ago

The compound HNO3 can be described as an

xz_007 [3.2K]

The answer is (1) Arrhenius acid and an electrolyte. The HNO3 is a H+ ion donor and OH- receptor. Electrolyte means the compound will release ion when dissolving in suitable ionized solution.

6 0

3 years ago

What is the Molarity of a solution with 1.8 mil KCl dissolved to a volume of 1.5L

vova2212 [387]

Answer:1.2M

Explanation:

Molarity=number of moles ➗ volume in liters

Molarity=1.8 ➗ 1.5

Molarity=1.2M

8 0

3 years ago

How many atoms are in 3Na2SO4

Virty [35]

There are 2 atoms in 3Na2SO4

5 0

2 years ago