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The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes and 816X and 818X in the sample? - Science

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प्रश्न

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes `""_8^16X" and """_8^18X` in the sample?

योग
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उत्तर

It is given that the average atomic mass of the sample of element X is 16.2 u.

Therefore,

The atomic mass of the given element X is = 16.2 u.

Let `""_8^16 X` percentage = a

Then `""_8^18X` percentage = (100 − a)

Average mass of X = `16("a"/100) + 18((100 - "a")/100)`

16.2 = `((16"a")/100) + ((1800 - 18"a")/100)`

1620 = 1800 − 2a

1800 - 1620 = 2a

180 = 2a

a = `180/2` 

a = 90

Therefore `""_8^16X"` percentage = 90%

And `""_8^18X"` percentage = 100 − 90

= 10%

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अध्याय 4: Structure of the Atom - Exercises [पृष्ठ ५५]

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एनसीईआरटी Science [English] Class 9
अध्याय 4 Structure of the Atom
Exercises | Q 11 | पृष्ठ ५५

वीडियो ट्यूटोरियलVIEW ALL [3]

संबंधित प्रश्न

MATCH THE COLUMNAS

1. Jpham  Dalton a. Neutrons
2. Atom b. Model of the atom
3. Chadwick c.The atomic theory of matter 
4. Rutherfrod d. Positively  charged 
5. Protons e. Electricity neutral 
6. Nuclear  fusion  f. Generator of electricity 
7.Gamma -rays  g. High penetrating power 
  h.Energy in sun 

TRUE \ FALSE

Elements having a tendency to accept electrons are called metals

 


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