An atom with [tex]$Z=26$[/tex] and [tex]$A=58$[/tex] contains protons and neutrons.
A. 26; 84
B. 26; 58
C. 58; 26
D. 26; 32
E. 32; 26
Answer (1)
The number of protons equals the atomic number: Z = 26 .
The number of neutrons equals the mass number minus the atomic number: A − Z = 58 − 26 .
Calculate the number of neutrons: 58 − 26 = 32 .
The atom contains 26 protons and 32 neutrons.
Explanation
Problem Analysis We are given an atom with atomic number Z = 26 and mass number A = 58 . We need to find the number of protons and neutrons in the atom.
Finding Number of Protons The number of protons in an atom is equal to its atomic number, Z . Therefore, the number of protons is 26.
Finding Number of Neutrons The number of neutrons in an atom is equal to the difference between its mass number, A , and its atomic number, Z . Therefore, the number of neutrons is A − Z = 58 − 26 .
Calculating Number of Neutrons Calculating the number of neutrons: 58 − 26 = 32 .
Final Answer Therefore, the atom contains 26 protons and 32 neutrons.
Examples
Understanding the composition of atoms is fundamental in chemistry and physics. For example, in nuclear medicine, radioactive isotopes are used for diagnostic imaging and treatment. The number of protons determines the element, while the number of neutrons affects the isotope's stability and radioactive properties. Knowing the number of protons and neutrons helps scientists predict how an atom will behave in various chemical reactions and nuclear processes. This knowledge is also crucial in fields like materials science, where the properties of materials are often determined by their atomic composition.
