Which of the following is an incorrect representation for a neutral atom?
(a) ${ }_3^6 Li $
(b) ${ }_6^{13} C$
(c) ${ }_{30}^{63} Cu$
(d) ${ }_{15}^{30} P$
(e) ${ }_{47}^{108} Ag$
Answer (2)
C
Explanation
Understanding the Problem We want to identify the incorrect representation of a neutral atom from the given options. A neutral atom has an equal number of protons and electrons. The subscript in the notation Z A X represents the atomic number (Z), which is the number of protons. The superscript represents the mass number (A), which is the total number of protons and neutrons.
Analyzing Each Option (a) 3 6 L i : Lithium (Li) has an atomic number of 3. The representation is correct. (b) 6 13 C : Carbon (C) has an atomic number of 6. The representation is correct. (c) 30 63 C u : Copper (Cu) has an atomic number of 29, not 30. Therefore, this representation is incorrect. (d) 15 30 P : Phosphorus (P) has an atomic number of 15. The representation is correct. (e) 47 108 A g : Silver (Ag) has an atomic number of 47. The representation is correct.
Identifying the Incorrect Representation The incorrect representation is (c) 30 63 C u because copper has an atomic number of 29, not 30.
Final Answer The incorrect representation for a neutral atom is (c) 30 63 C u .
Examples
Understanding the structure of atoms and their representation is fundamental in chemistry. For example, in nuclear medicine, radioactive isotopes are used for diagnostic imaging and treatment. Knowing the correct atomic number and mass number is crucial for selecting the appropriate isotope and calculating the radiation dose. Similarly, in materials science, the properties of materials are often related to their atomic composition, making the correct representation of atoms essential for designing new materials.
The incorrect representation for a neutral atom is (c) 30 63 C u because copper has an atomic number of 29, not 30. Other options correctly represent their respective elements. Therefore, the answer is option (c).
;
