Write the correct symbol, with both superscript and subscript, for each of the following. Use the list of elements in the front inside cover as needed: (a) the isotope of platinum that contains 118 neutrons

Verified step by step guidance

1. Identify the atomic number of platinum (Pt) from the periodic table, which is 78.
2. Determine the mass number of the isotope by adding the number of protons (atomic number) and the number of neutrons: Mass number = 78 (protons) + 118 (neutrons).
3. Write the isotope notation using the element symbol (Pt), the mass number as a superscript, and the atomic number as a subscript.
4. The isotope notation will be in the form: \( ^{\text{mass number}}_{\text{atomic number}}\text{Element Symbol} \).
5. Substitute the values into the notation: \( ^{196}_{78}\text{Pt} \).

Key Concepts

Isotopes

Isotopes are variants of a particular chemical element that have the same number of protons but different numbers of neutrons. This difference in neutron count results in varying atomic masses. For example, platinum typically has an atomic number of 78, meaning it has 78 protons, but its isotopes can have different neutron counts, such as the one with 118 neutrons.

Nuclear Notation

Nuclear notation is a way of representing isotopes using the element's symbol, along with its atomic number and mass number. The mass number, which is the sum of protons and neutrons, is written as a superscript, while the atomic number is written as a subscript. For platinum with 118 neutrons, the mass number would be 196 (78 protons + 118 neutrons), leading to the notation 196/78Pt.

Atomic Number and Mass Number

The atomic number is the number of protons in an atom's nucleus and defines the element. The mass number is the total number of protons and neutrons in the nucleus. Understanding these two numbers is crucial for identifying isotopes and writing their correct nuclear symbols, as they provide essential information about the atom's structure and identity.