Select the pairs of isobars and isotones from the following nuclei: Na 23 11 , Mg 24 12 , Na 24 11 , Ne 23 10 .

Isobars are the nuclei, which have the same atomic mass (mass number). Out of the given nuclei Mg 24 12 , Na 24 11 have the same mass number 24 , hence these are isobars Na 24 11 , Ne 24 10 have the same mass number 23 , hence these are also isobars Isotones are the nuclei, which have the same number of neutrons. The given nuclei Na 23 11 , Mg 24 12 both have 23 - 11 = 24 - 12 = 12 same number of neutrons, hence are isotones. Similarly, the nuclei Na 24 11 , Ne 23 10 have 24 - 11 = 23 - 10 = 13 have same number of neutrons, hence are also isotones.

How many α -particles will be emitted by the decay of Th 228 90 into Pb 212 82 ?

The alpha particle is doubly ionised helium atom i.e He + + 2 4 . It is clear that the emission of this from a nucleus will reduce the atomic number by 2 and mass number by 4 . The given equation is Th 228 90 → Pb 212 82 The difference in atomic number between the two is 90 - 82 = 8 which is due to 8 2 = 4 alpha particles The difference of mass number between the two is 228 - 212 = 16 which is due to 16 4 = 4 alpha particle Therefore, the number of alpha particle emitted in the reaction is 4 .

An alpha-particle is emitted from the nucleus of U 238 92 . How many protons and neutrons are left in the nucleus?

As the emission of alpha particle from the nucleus will reduce the mass number by 4 and the charge number by 2 , the new nucleus can be represented by X 92 - 2 238 - 4 or X 90 234 The daughter nucleus has atomic number= 90 and the mass number = 234 The number of protons in daughter nucleus 92 - 2 = 90 . The number of neutrons in the daughter nuclei are mass number - atomic number = 234 - 90 - 144 Therefore 90 protons and 144 neutrons are left in the daughter nucleus

How many protons and neutrons will be left in Th 234 90 nucleus after emitting a β -particle?

As we know that each beta decay will increase the charge number by one without any change in the mass number After emission of one beta particle, the nucleus of Th 90 234 will become X 90 + 1 234 - 0 . Thus, this nucleus will have 91 protons and 234 - 91 = 143 neutrons

How many neutrons will be left in Pb 210 82 nucleus after emitting a β -particle?

As we know that each beta decay will increase the charge number by one without any change in the mass number After the emission of one beta particle, the nucleus of P 82 210 b will become P 82 + 1 210 b = P 83 210 b . Thus, this nucleus will have 83 protons and 210 - 83 = 127 neutrons

E M B I B E

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 17

MEDIUM

12th ICSE

IMPORTANT

Earn 100

Select the pairs of isobars and isotones from the following nuclei: $_{6} C^{14},_{7} N^{13},_{7} N^{14},_{8} O^{16}$ .

Important Questions on Nuclear Structure

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12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 18

Select the pairs of isobars and isotones from the following nuclei: ${}_{11}{Na}^{23}, {}_{12}{Mg}^{24}, {}_{11}{Na}^{24}, {}_{10}{Ne}^{23}$ .

MEDIUM

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 19

How many

α

-particles will be emitted by the decay of

{}_{90}{Th}^{228}

into

{}_{82}{Pb}^{212}

?

MEDIUM

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 20

An alpha-particle is emitted from the nucleus of ${}_{92}U^{238}$ . How many protons and neutrons are left in the nucleus?

EASY

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 21

An atom, represented by ${}_{Z}X^{A}$ , emits $n α$ -particles. How many protons will be left in it after this and what will be the atomic number of the new atom?

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 22

Give the atomic number and mass number of the nucleus

Y

in the reaction

{}_{Z}X^{A} \to α + Y

.

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IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 23

A ${}_{92}U^{238}$ nucleus is finally converted into thorium nucleus after emitting $2$ alpha particles and $2$ beta particles respectively. What will be the atomic number and the mass number of thorium nucleus so obtained?

EASY

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 24

How many protons and neutrons will be left in ${}_{90}{Th}^{234}$ nucleus after emitting a $β$ -particle?

EASY

12th ICSE

IMPORTANT

ISC Physics Class 12, Part-2>Chapter 14 - Nuclear Structure>QUESTIONS>Q 25

How many neutrons will be left in