Final answer:
Isotopes are written by placing the mass number as a superscript and the atomic number as a subscript before the element's symbol. Radon-220, Polonium-210, and Gold-197 are symbolized as ¹²⁰Rn, ¹⁰Po, and ¹⁷Au, respectively. Knowing the atomic and mass numbers is essential for correctly writing isotope symbols.
Explanation:45
To write symbols for the following isotopes, you need to include both the atomic number and the mass number for each. The atomic number is written as a subscript to the left of the element symbol, and the mass number is written as a superscript to the left of the element symbol. Here are the symbols for the isotopes you’ve mentioned:
- Radon-220: ¹²⁰Rn (where 86 is the atomic number of radon and 220 is the mass number)
- Polonium-210: ¹⁰Po (where 84 is the atomic number of polonium and 210 is the mass number)
- Gold-197: ¹⁷Au (where 79 is the atomic number of gold and 197 is the mass number)
It’s essential to remember that each element has a unique atomic number, which defines the number of protons in the nucleus of the atom and hence, the identity of the element. The mass number represents the total number of protons and neutrons in the atom, and different isotopes of the same element have different mass numbers because they have different numbers of neutrons.