Atomic Number

The atomic number of an element is the number of protons in the nucleus of an atom. It is represented by the letter Z. The atomic number is a fundamental property of an element and determines its identity in the periodic table.

Key Points to Remember:

1. The atomic number is unique to each element and does not change for a given element.
2. The atomic number determines the element's identity and its position in the periodic table.
3. Atoms of the same element have the same atomic number, but they can have different numbers of neutrons, leading to the existence of isotopes.
4. The atomic number is always a whole number and is typically found above the symbol of the element in the periodic table.

Study Guide

Here are some key points and questions to help you understand and remember the concept of atomic number:

Definition:

Define atomic number and explain its significance in determining the identity of an element.

Location in the Periodic Table:

Explain where the atomic number is located in the periodic table and how it is used to organize the elements.

Relationship to Protons:

Describe the relationship between the atomic number and the number of protons in an atom.

Isotopes:

Explain how isotopes of an element are related to the atomic number and the number of neutrons.

Practice Problems:

Provide examples of elements and their atomic numbers, and practice writing the atomic symbols for different elements.