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MHT CET20243 May 2024Morning ShiftChemistryStructure of AtomActual

What is the representation of an element having mass number of 40 and 21 neutrons in it?

Options

  1. A₁₈⁴⁰ X
  2. B₁₉⁴⁰ X
  3. C₁₂⁴⁰ X
  4. D₂₀⁴⁰ X

Correct answer

B. ₁₉⁴⁰ X

Step-by-step solution

3. Protons (Z) : The number of protons can be determined by subtracting the number of neutrons from the mass number: Z=A-N=40-21=19 So, the element has 19 protons. 4. Element symbol: The element with 19 protons is potassium (K), which has the atomic number 19. Thus, the correct representation of the element is K-40 or ₁₉⁴⁰ ~K . Therefore, the correct answer is: (B) ₁₉⁴⁰ X .

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