Import Question JSON

Current Question (ID: 7468)

Question:

$\text{An element with a mass number of 81 contains 31.7% more neutrons as compared to protons. The atomic symbol of the element would be:}$

Options:

1. $^{81}_{35}\text{Br}$
2. $^{81}_{36}\text{Br}$
3. $^{79}_{35}\text{Br}$
4. $^{79}_{36}\text{Br}$

Solution:

$\text{Hint: Mass number = number of proton + number of neutron}$ $\text{Step 1:}$ $\text{Calculate the number of neutron in the molecule}$ $\text{Let the number of protons in the element be x.}$ $\text{Number of neutrons in the element} = x + 31.7\% \text{ of } x = x + 0.317x = 1.317x$ $\text{Step 2:}$ $\text{Calculate the number of proton as follows:}$ $\text{According to the question,}$ $\text{Mass number of the element} = 81$ $\text{(Number of protons + number of neutrons)} = 81$ $1.317x = 81$ $x = \frac{81}{2.317} = 35$ $\text{Hence, the number of protons in the element i.e., x is 35.}$ $\text{Since the atomic number of an atom is defined as the number of protons present in its nucleus, the atomic number of the given element is 35.}$ $\text{The atomic symbol of the element is } ^{81}_{35}\text{Br}$

Import JSON File

Upload a JSON file containing LaTeX/MathJax formatted question, options, and solution.

Expected JSON Format:

{
  "question": "The mass of carbon present in 0.5 mole of $\\mathrm{K}_4[\\mathrm{Fe(CN)}_6]$ is:",
  "options": [
    {
      "id": 1,
      "text": "1.8 g"
    },
    {
      "id": 2,
      "text": "18 g"
    },
    {
      "id": 3,
      "text": "3.6 g"
    },
    {
      "id": 4,
      "text": "36 g"
    }
  ],
  "solution": "\\begin{align}\n&\\text{Hint: Mole concept}\\\\\n&1 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\text{ moles of carbon atom}\\\\\n&0.5 \\text{ mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6] = 6 \\times 0.5 \\text{ mol} = 3 \\text{ mol}\\\\\n&1 \\text{ mol of carbon} = 12 \\text{ g}\\\\\n&3 \\text{ mol carbon} = 12 \\times 3 = 36 \\text{ g}\\\\\n&\\text{Hence, 36 g mass of carbon present in 0.5 mole of } \\mathrm{K}_4[\\mathrm{Fe(CN)}_6].\n\\end{align}",
  "correct_answer": 4
}