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NEET2019ChemistrySome Basic Concepts of ChemistryActual

An element with mass number 81 contains 31.7 % more neutrons as compared to protons. It symbol is

Options

  1. A₄₀ x⁸¹
  2. B₃₅ x⁸¹
  3. C₈₁ x³¹⁷
  4. D₄₀ x⁸¹

Correct answer

B. ₃₅ x⁸¹

Step-by-step solution

Let, the number of protons = x Number of neutrons = x + 31.7 x 100 = 131.7 x 100 mass number = number of protons + number of neutrons 81=x+ 131.7 x 100 x =35 Thus, the symbol of the element is ₃₅ X⁸¹ .

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