Atomic Structure and Arrangement

Atoms

• The smallest particle of an element that still retains the properties of that element.

Sub-atomic particles

• The smaller particles that constitute an atom, including protons, neutrons, and electrons.

Subatomic Particles Details

• Protons

  • Symbol: $p^{+}$

  • Location: Nucleus

  • Charge: +1

  • Mass: 1 amu

• Neutrons

  • Symbol: $n^{0}$

  • Location: Nucleus

  • Charge: 0

  • Mass: 1 amu

• Electrons

  • Symbol: $e^{-}$

  • Location: Electron cloud around the nucleus

  • Charge: -1

  • Mass: 0.0005 amu

Bohr Model

• Illustrates a nucleus containing neutrons and protons, surrounded by electrons in specific energy levels or orbits.

• Key components: Nucleus (protons & neutrons), Electrons.

• Nucleons: Refers to both protons and neutrons in the nucleus.

Isotopes

• Atoms of the same element that have different numbers of neutrons.

• Isotopes possess the same atomic number but different mass numbers.

Nuclide Notation

• A symbolic representation of atoms providing information about the nucleus and the chemical symbol.

• General Form: $\begin{matrix} A \ Z \end{matrix} X$

  • $X$ = Chemical symbol

  • $A$ = Mass number (number of protons & neutrons)

  • $Z$ = Atomic number (number of protons)

• Purpose: Helps to identify specific isotopes of elements.

Electron Arrangement

• Electrons are arranged in energy levels based on specific rules.

  • First energy level: Maximum of 2 electrons

  • Second energy level: Maximum of 8 electrons

  • Third energy level: Maximum of 8 electrons (for basic atomic models)