On the periodic table of elements, the atomic number and the mass number are typically provided for each element. Here's where you can find these values:
Atomic number: The atomic number is usually displayed above or below the element's symbol. It is represented by the whole number on the top left or bottom left of the element's box. For example, hydrogen (H) has an atomic number of 1, carbon (C) has an atomic number of 6, and oxygen (O) has an atomic number of 8.
Mass number: The mass number is not explicitly listed on the periodic table. Instead, the average atomic mass or atomic weight of the element is typically provided. The average atomic mass considers the relative abundance of different isotopes of the element. It is usually found in decimal form either below the element's symbol or within its box. The average atomic mass represents the weighted average of the masses of all the naturally occurring isotopes of the element. It can help determine the number of neutrons indirectly by subtracting the atomic number from the mass number.
It's important to note that the values displayed on the periodic table for average atomic mass are often rounded to simplify their representation. If you need more precise values or information on specific isotopes, you may need to refer to more detailed resources or scientific databases.
Overall, the atomic number is prominently displayed on the periodic table, while the mass number (or average atomic mass) is provided as a more general value representing the element's isotopic composition.