The radioactive isotope cesium-137 was produced in large amounts in fallout from the 1985 nuclear power plant disas-ter at Chernobyl, Ukraine. Write the symbol for this isotope in standard format.

Verified step by step guidance

1. Identify the element: Cesium is represented by the symbol 'Cs'.
2. Determine the mass number: The mass number for this isotope is given as 137.
3. Determine the atomic number: Cesium has an atomic number of 55, which is the number of protons in the nucleus.
4. Combine the information: The standard format for an isotope is written as \( ^{A}_{Z} \text{Element} \), where \( A \) is the mass number and \( Z \) is the atomic number.
5. Write the symbol: For cesium-137, the symbol is \( ^{137}_{55} \text{Cs} \).

Key Concepts

Isotopes

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This results in different atomic masses for the isotopes of the same element. For example, cesium-137 has 55 protons and 82 neutrons, distinguishing it from other isotopes of cesium.

Nuclear Notation

Nuclear notation is a way of representing isotopes using the element's symbol, the mass number, and the atomic number. The mass number is written as a superscript to the left of the element symbol, while the atomic number is written as a subscript. For cesium-137, the notation is represented as ¹³⁷Cs, where 137 is the mass number.

Radioactivity

Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation. This can occur in the form of alpha particles, beta particles, or gamma rays. Cesium-137 is a radioactive isotope that decays by beta emission, making it significant in discussions of nuclear fallout and environmental impact.