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just olya [345]
3 years ago
8

An element has two naturally occurring isotopes, X-85 with a mass of 84.9118 amu and a natural abundance of 72.17%, and X-87 wit

h a mass of 86.9092 amu and a natural abundance of 27.83%. Calculate the atomic mass of this element.
Chemistry
1 answer:
QveST [7]3 years ago
5 0

Answer:

This element is Rubidium (Rb) and has an average atomic mass of 85.468 u

Explanation:

The average mass of an element is calculated by taking the average of the atomic masses of its stable isotopes.

The enitre atomic mass = 100 % or 1

⇒ this consists of X-85 with 72.17 % abundance  with atomic massof  84.9118 g/mol

72.17 % = 0.7217

⇒ this consists of X-87 with  27.83 % abundance with atomic mass of 86.9092 g/mol

27.83 % = 0.2783

To calculate the mass of this isotope we use the following:

0.7271 * 84.9118 + 0.2783 * 86.9092 =85.468 g/mol

This element is Rubidium(Rb) and has an average atomic mass of 85.468 u

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Svet_ta [14]

Answer:

Now that you have the knowledge of the highest specific heat capacity and lowest porosity, which material would you choose to build Rover's new doghouse roof?

Oak has the highest heat capacity; therefore, oak can absorb a lot of heat without raising its temperature. This is good for very hot areas. Concrete has the lowest porosity so water will not leak through its pores and drip into the doghouse. This is good for rainy areas. However, clay is second on both lists and might be a good choice overall for hot and rainy weather conditions. Rover should be happy with this.

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Have a great day!

7 0
3 years ago
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Use dimensional analysis to convert 14.5mi/hr to km/s
Liula [17]

Answer:

0.006 48 km/s

Explanation:

1. Convert miles to kilometres

14.5 mi × (1.609 km/1 mi) = 23.33 km

2. Convert hours to seconds

1 h × (60 min/1h) × (60 s/1 min) = 3600 s

3. Divide the distance by the time

14.5 mi/1 h = 23.3 km/3600 s = 0.006 48 km/s

5 0
3 years ago
Inside stars in space, the nuclei of hydrogen atoms fuse together to form helium atoms. This represents which form of energy?
mixas84 [53]

Explanation:

When two small nuclei combine together to form a large nuclei then it is known as nuclear fusion.

When nuclei of two hydrogen atoms fuse together then it results in the formation of a helium atom along with the release of lot of energy. This energy is nuclear energy.

This nuclear reaction is as follows.

      ^{2}_{1}H + ^{3}_{1}H \rightarrow ^{4}_{2}He + ^{1}_{0}n + Energy

Thus, we can conclude that nuclear fusion represents nuclear energy.


6 0
3 years ago
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L20_UENAxleFsh-VHfg9rLfZsitva3L3UKGjmF1B299/vie Settle a dispute. X Anya claims that this challenge can be solved with a single
Fynjy0 [20]

Answer:

Neither arre correct

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Neither Anya nor Braden are correct. This is because if you use 90 degrees, 180 degrees, or even 270 degrees you will not get the exact image, which means that the image will not be found by just a rotation because there will be a curve in the image. You can solve it if you can do 90 degree rotation and translation.

4 0
3 years ago
Two protons and two neutrons are released as a result of this reaction.
Murljashka [212]

<u>Answer:</u> The particle released in the given reaction is one alpha particle

<u>Explanation:</u>

In a nuclear reaction, the total mass and total atomic number remains the same.

For the given fission reaction:

^{222}_{86}\textrm{Rn}\rightarrow ^A_Z\textrm{X}+^{218}_{84}\textrm{Po}

  • <u>To calculate A:</u>

Total mass on reactant side = total mass on product side

222 = A + 218

A = 4

  • <u>To calculate Z:</u>

Total atomic number on reactant side = total atomic number on product side

86 = Z + 84

Z = 2

The isotopic symbol of unknown element is _{2}^{4}\textrm{He}. Another name of helium atom is alpha particle.

Hence, the particle released in the given reaction is one alpha particle

3 0
3 years ago
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