(c) An atom has the electron configuration 1s²2s²2p⁶3s²3p². How many valence electrons does the atom have?

Key Concepts

Electron Configuration

Electron configuration describes the distribution of electrons in an atom's orbitals. It is represented by a series of numbers and letters indicating the energy levels and types of orbitals occupied by electrons. Understanding electron configuration is essential for determining the chemical properties of an element, including its reactivity and bonding behavior.

Valence Electrons

Valence electrons are the electrons in the outermost shell of an atom that are involved in chemical bonding. They determine how an atom interacts with other atoms and are crucial for understanding an element's reactivity. The number of valence electrons can be deduced from the electron configuration, particularly from the highest principal energy level.

Principal Energy Levels

Principal energy levels are the layers of electrons surrounding the nucleus of an atom, denoted by the principal quantum number (n). Each level can hold a specific number of electrons, and the outermost level contains the valence electrons. Identifying the principal energy levels helps in understanding the structure of the atom and predicting its chemical behavior.