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algol [13]
2 years ago
11

N 1868, helium was discovered by looking at the sun almost thirty years before it was discovered on earth. How was that possible

?
Group of answer choices

a,The size of the sun flares suggested that the matter was twice the mass of hydrogen

b,They captured cosmic rays from the sun that had helium in it

c,They found a meteorite that contained helium

d,By looking at the light from the sun they found a spectrun of light that was not from any known element
Chemistry
1 answer:
Free_Kalibri [48]2 years ago
5 0

Answer:

a im not sure tho

Explanation:

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A gas has an initial volume of 455 mL at 105ºC and a final volume of 235 mL. What is its final temperature in Celsius degrees?
Oksana_A [137]
Hello!

To solve this problem we're going to use the Charles' Law. This Law describes the relationship between Volume and Temperature in an ideal gas. Applying this law we have the following equation:

\frac{V1}{T1} = \frac{V2}{T2} \\  \\ T2= \frac{V2*T1}{V1}=  \frac{235 mL * 105  ^{\circ}C }{455 mL}=54,23 ^{\circ}C

So, the final temperature is 54,23 °C

Have a nice day!
5 0
3 years ago
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What is the mass, in pounds, of 389 mL of a gas that has a density of 1.29 g/L?
devlian [24]

Answer: Mass of gas is 0.001 pounds.

Explanation:

Density is defined as the mass contained per unit volume.

Density=\frac{mass}{Volume}

Given : Mass of gas = ?

Density of gas = 1.29g/L

Volume of gas = 389 ml = 0.389 L     (1L=1000ml)

Putting in the values we get:

1.29g/L=\frac{mass}{0.389L}

mass=0.5grams  

mass=0.5\times 0.002lb=0.001lb       (1g =0.002 lb)

Thus the mass of gas is 0.001 pounds.

7 0
2 years ago
___Mg + ___Fe2O3 -> ___MgO + ___Fe
kipiarov [429]
3 Mg, 0 Fe2O3, 3MgO, 2 Fe
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2 years ago
What is the meaning of nucleus<br>​
IrinaVladis [17]

the nucleus is an organelle containing the cell's chromosomes

8 0
2 years ago
(4) Calculate the % of a compound that can be removed from liquid phase 1 by using ONE to FOUR extractions with a liquid phase 2
maksim [4K]

Answer:

One extraction: 50%

Two extractions: 75%

Three extractions: 87.5%

Four extractions: 93.75%

Explanation:

The following equation relates the fraction q of the compound left in volume V₁ of phase 1 that is extracted n times with volume V₂.

qⁿ = (V₁/(V₁ + KV₂))ⁿ

We also know that V₂ = 1/2(V₁) and K = 2, so these expressions can be substituted into the above equation:

qⁿ = (V₁/(V₁ + 2(1/2V₁))ⁿ = (V₁/(V₁ + V₁))ⁿ =  (V₁/(2V₁))ⁿ = (1/2)ⁿ

When n = 1, q = 1/2, so the fraction removed from phase 1 is also 1/2, or 50%.

When n = 2, q = (1/2)² = 1/4, so the fraction removed from phase 1 is (1 - 1/4) = 3/4 or 75%.

When n = 3, q = (1/2)³ = 1/8, so the fraction removed from phase 1 is (1 - 1/8) = 7/8 or 87.5%.

When n = 4, q = (1/2)⁴ = 1/16, so the fraction removed from phase 1 is (1 - 1/16) = 15/16 or 93.75%.

5 0
2 years ago
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