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As the Mass Number a Increases, Which of the Following Quantities Related to a Nucleus Do Not Change?

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प्रश्न

As the mass number A increases, which of the following quantities related to a nucleus do not change?

विकल्प

  • Mass

  • Volume

  • Density

  • Binding energy

MCQ
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उत्तर

Density

Radius of a nucleus with mass number A is given as `R = R_0A^1"/"3`

Here, Ro = 1.2 fm

therefore Volume of the nucleus = `(4piR^3)/3 = (4piR_0^3A)/3`

This depends on A. With an increase in A, V increases proportionally.
Mass of the nucleus \[\simeq\] AmN

Here, mN is the mass of a nucleon.
Therefore, mass of the nucleus also increases with the increasing mass number.
Binding energy also depends on mass number (number of nucleons) as it is the difference between the total mass of the constituent nucleons and the nucleus. Therefore, it also varies with the changing mass number.

On the other hand,

`Density = "Mass"/"Volume" = (Am_N)/(4piR^3"/"3) = (Am_N)/(4piR_0^3A"/"3) = (m_N)/(4piR_0^3"/"3) = (3m_N)/(4piR_0^3)`

This is independent of A and hence does not change as mass number increases.

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अध्याय 46: The Nucleus - MCQ [पृष्ठ ४४१]

APPEARS IN

एचसी वर्मा Concepts of Physics Volume 1 and 2 [English]
अध्याय 46 The Nucleus
MCQ | Q 1 | पृष्ठ ४४१

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