Question

Write the symbol for each isotope in the form \({ }_{Z}^{A} X\). (a) U-235 (b) V-52 (c) P-32 (d) \(\mathrm{Xe}-144\)

Short answer

Uranium-235: \( \_\{92\}^{235}U \), Vanadium-52: \( \_\{23\}^{52}V \), Phosphorus-32: \( \_\{15\}^{32}P \), Xenon-144: \( \_\{54\}^{144}Xe \)

Step-by-step solution

Determine Protons and Mass Number - Uranium-235

Identify the number of protons (atomic number Z) for Uranium (U), which is 92. The mass number (A) is given as 235.

Write Uranium-235 Isotope Symbol

Write the symbol for Uranium-235 isotope as \( \_\{92\}^{235}U \).

Determine Protons and Mass Number - Vanadium-52

Identify the number of protons (atomic number Z) for Vanadium (V), which is 23. The mass number (A) is given as 52.

Write Vanadium-52 Isotope Symbol

Write the symbol for Vanadium-52 isotope as \( \_\{23\}^{52}V \).

Determine Protons and Mass Number - Phosphorus-32

Identify the number of protons (atomic number Z) for Phosphorus (P), which is 15. The mass number (A) is given as 32.

Write Phosphorus-32 Isotope Symbol

Write the symbol for Phosphorus-32 isotope as \( \_\{15\}^{32}P \).

Determine Protons and Mass Number - Xenon-144

Identify the number of protons (atomic number Z) for Xenon (Xe), which is 54. The mass number (A) is given as 144.

Write Xenon-144 Isotope Symbol

Write the symbol for Xenon-144 isotope as \( \_\{54\}^{144}Xe \).

Key concepts

Atomic Number

The atomic number, denoted by the symbol Z, is a fundamental property of an element and its atoms. It represents the number of protons found in the nucleus of an atom and uniquely identifies a chemical element. For example, all atoms with an atomic number of 1 are hydrogen atoms, while an atomic number of 6 denotes carbon. In isotope notation, the atomic number is displayed as a subscript to the lower left of the chemical symbol. Understanding atomic numbers is crucial because it not only defines the element but also its position in the periodic table. The atomic number further dictates the chemical behavior of the element, as it determines the electron configuration, which is responsible for the atom's reactivity and bonding characteristics.

When solving problems like the one given, always use the periodic table to find the correct atomic number for the required chemical element.

Mass Number

The mass number, symbolized as A, refers to the total count of protons and neutrons within an atom's nucleus. It is indicative of an atom's mass when compared to that of other atoms. Unlike the atomic number (Z), the mass number (A) can vary among different isotopes of the same element due to a different number of neutrons. In isotope notation, the mass number is placed as a superscript to the upper left of the chemical symbol.

In the aforementioned exercise, identifying the mass number is as straightforward as reading it from the isotope's name, for example, U-235 has a mass number of 235. It's important to note that while atomic number remains constant for a given element, mass number changes across isotopes, which is why isotopes exhibit different physical properties while retaining the same chemical properties.

Chemical Symbols

Chemical symbols are abbreviations used to represent chemical elements. These symbols are derived from either the English names of elements or their Latin names. For instance, H stands for hydrogen, and Fe originates from 'ferrum,' the Latin word for iron. In isotope notation, the chemical symbol is central to the notation and usually follows the atomic and mass numbers, which are placed on its left side. Each element has a unique symbol, ensuring clear communication in written chemical language.

In practical exercises like the one provided, students must ensure they use the correct chemical symbol for the element in question. This becomes especially imperative in complex chemical formulas and reactions to avoid confusion with other elements.

Nuclear Chemistry

Nuclear chemistry deals with the processes, reactions, and transformations that occur within the atomic nucleus. Isotopes are a key topic in this field as they are atoms of the same element that differ in neutron count and therefore mass number. These differences can dramatically influence the stability of the nucleus and cause some isotopes to be radioactive.

In the context of the exercise, one can see the practical application of nuclear chemistry principles in determining the correct isotope symbols, which are not only important for nuclear reactions but also in understanding decay processes, calculating nuclear binding energy, and various applications in medicine and energy production. Students looking to master isotope notation will benefit from a solid understanding of nuclear chemistry as it provides a backdrop for the isotope's existence and characteristics.