Electrons

Definition

Electrons are subatomic particles with a negative charge that orbit the nucleus of an atom. They play a crucial role in chemical bonding and reactions.

5 Must Know Facts For Your Next Test

1. Electrons are located in energy levels or electron shells around the nucleus.
2. The number of electrons determines an atom's reactivity and its ability to form bonds.
3. In a neutral atom, the number of electrons is equal to the number of protons.
4. Electron configurations follow the Pauli exclusion principle, Hund's rule, and the Aufbau principle.
5. Valence electrons are the outermost electrons and determine an element's chemical properties.

Review Questions

• What is the charge of an electron?
• How do valence electrons affect an atom's chemical behavior?
• What principles govern electron configurations in atoms?

Related terms

Proton:

Positively charged subatomic particle found in the nucleus of an atom.

Neutron: Neutrally charged subatomic particle found in the nucleus of an atom.

Ion:

An atom or molecule that has gained or lost one or more electrons, resulting in a net charge.