Science, asked by singhjagga160p74pb6, 1 year ago

find 1. the total no. of neutrons 2. the total mass of neutron in 7mg of C14

Answers

Answered by Sanskriti101199
376
The molar mass of 14C is 14g. Therefore we will first calculate the number of moles in 7mg (or 0.007 g) of 14C.

Number of moles in 0.007 g of 14C = mass / molar mass

= 0.007 / 14 = 0.0005 moles

Now 1 mole of 14C = 6.023 X 1023 atoms of 14C

Therefore 0.0005 moles of 14C = 0.0005 X 6.023 X 1023 atoms of 14C

= 3.015 X 1020 atoms of 14C

Now 1 atom of 14C contains 6 protons (atomic number of Carbon is 7).

Therefore there are 8 neutrons present in 1 atom of 14C.

Thus 1 atom of 14C = 8 neutrons

Therefore

3.015 X 1020 atoms of 14C = 8 X 3.015 X 1020 neutrons of 14C

= 2.412 X 1021 neutrons of 14C

Now mass of 1 neutrons = 1.675 X 10-27 Kg

Therefore mass of 2.412 X 1021 neutrons of 14C = 2.412 X 1021 X 1.675 X 10-27 Kg

= 4.04 X 10-6 Kg



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Answered by Yush20
91

Answer:

Here we have 14C i.e Carbon with mass number = 14

Therefore No of protons + noi of neutrons = 14

Now Atomic no of carbon = No of protons = 6

Therefore No of neutrons are 14 - 6 = 8

Since 14 is the mass no of this isotope of carbon.

That means 14 gram of this carbon will contain 6.02*10^23 ( Avogadro's number) atoms of 14C

Now one atom of 14 C contains 8 neutrons there fore 14 gram of 14C will contain 8 * (6.02*10^23)

That means

14 * 1000 mg ( I gram = 1000 mg) will have 8 * (6.02 * 10^23) neutrons.

14 mg will have [8* (6.02*10^23) ] /1000 = 8 * (6.02 * 10^20)

1 mg = [ 8 * (6.02 * 10^20) ] /14

7 mg = [8 * (6.02 * 10^20) *7 ] / 14

That will be around 24 * 10^20   because you will have to assume Avogadro's number to  be 6 * 10^23

So we have Total no of Neutrons equal to 24 * 10^20

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Now We know that mass of a neutron is 1.675 * 10^-27 kg

No of neutrons in 7 mg of 14 C = 24 * 10^20 as we calculated above.

So total mass of neutrons will be [ 1.675*10^-27 ] * [24 * 10^20]

That will be equal to 40.2 * 10^-7 kg

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