What diagram is used to illustrate the valence electrons of an element using the element's symbol surrounded by dots?

The diagram that illustrates the valence electrons of an element using the element's symbol surrounded by dots is called the electron-dot structure. This representation, often referred to as Lewis dot structures, is designed to show the number of valence electrons that are available for bonding. Each dot represents a single valence electron, and they are placed around the symbol for the element to indicate how they might interact with other atoms to form bonds.

This method is particularly useful in predicting the types of bonds that an element might form, as well as understanding the molecule's structure and reactivity. For instance, knowing how many valence electrons an element has can help determine whether it is likely to donate, accept, or share electrons in chemical reactions. The simplicity and clarity of the electron-dot structure make it a fundamental tool in chemistry for visualizing and predicting chemical behavior.