Question

An element with mass number 81 contains 31.7% more neutrons as compared to protons. Assign the atomic symbol.

Answer 1

Given:

Mass number, A = 81
Number of neutrons = 31.7% more than protons

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Step 1: Define variables

Let number of protons = p

Number of neutrons = p + 31.7% of p

Number of neutrons = 1.317p

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Step 2: Use mass number relation

Mass number = Protons + Neutrons

81 = p + 1.317p

81 = 2.317p

p = 34.96 ≈ 35

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Step 3: Calculate neutrons

Number of neutrons = 81 − 35 = 46

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Step 4: Identify the element

Atomic number = 35

Element with atomic number 35 is Bromine (Br)

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Final Answer:

The atomic symbol of the element is:

⁸¹₃₅Br