Verified Answer :

  • The mass number \(A\) of an atom is calculated by summing the number of protons \(p\) and neutrons \(n\).
  • With \(p = 8\) and \(n = 10\), we calculate the sum: \(A = 8 + 10 = 18\).
  • The final result corresponds to option c, which is \(\boxed{18}\).

Explanation

  1. Problem Analysis and Definition of Mass Number

The problem asks for the mass number of an atom given the number of protons and neutrons. The mass number (\(A\)) is defined as the total number of nucleons in the nucleus, which is the sum of the number of protons (\(p\)) and the number of neutrons (\(n\)). The given values are \(p = 8\) and \(n = 10\).

  1. Calculation of Mass Number

To find the mass number (\(A\)), we use the formula:
\[A = p + n\]
Substituting the given values:
\[A = 8 + 10\]
\[A = 18\]
The mass number of the atom is the sum of its protons and neutrons.

  1. Final Answer Selection

Comparing the calculated value \(18\) with the provided options:

A\(2\)
B\(10\)
C\(18\)

The calculated value matches option c. Therefore, the mass number of the atom is \(18\). Thus, the correct option is \(\boxed{18}\).

Examples

In chemistry, understanding the composition of an atom is fundamental to identifying isotopes. For instance, Oxygen typically has 8 protons. If you encounter an oxygen isotope with 10 neutrons, you calculate its mass number as \(8 + 10 = 18\), identifying it as Oxygen-18. This simple arithmetic helps scientists track these isotopes in environmental studies or medical research.

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