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Stells [14]
4 years ago
9

what percentage do the elements hydrogen and helium account for in the universe? A. 100% B. 99.9% C. 98% D.99.8%

Chemistry
2 answers:
babunello [35]4 years ago
8 0
The percentage is 99.8% so D
den301095 [7]4 years ago
6 0
C. 98% this worlds atmostphere is mostly nitrogen tho

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Arlecino [84]
I wish i knew im sorry
3 0
3 years ago
A gas sealed in a drum container occupies 7.70 L at a sizzling 325C degrees. What will the volume be if the drum is quickly chi
grigory [225]

The volume of the drum after chilled quickly is 3.6 L.

<u>Explanation:</u>

As per the Charles Law, for any gas at constant pressure, volume of the gas is in direct proportion with the temperature measured in Kelvin. As the temperature increases, the gas expands and vice versa.

$\frac{V1}{T1} = \frac{V2}{T2} \\

After chilling the drum, the volume will get reduced and it can be found as,

V2 = $\frac{V1T2}{T1}

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Here the drum is chilled quickly, that is temperature is reduced and so the volume also decreases.

3 0
3 years ago
Arrange the following elements in order of increasing (from smallest to largest) atomic size: H, Br, Cl, O. Explain the reasonin
juin [17]

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When we move across a period in a periodic table then there will occur a decrease in atomic size of the atoms. But when we move across a group in a periodic table then there will occur an increase in atomic size of the atom.

Hydrogen is a period 1 element, oxygen is a period 2 element, chlorine is a period 3 element and bromine is a period 4 element.

Therefore, given elements are arranged in order of increasing atomic size as follows.

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3 years ago
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3 years ago
Why is it important to perform the reagent tests last?
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8 0
3 years ago
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