Particles

• In chemistry, particles refer to tiny units of matter that can exist independently or as part of larger structures.
• Particles can include atoms, molecules, ions, and subatomic particles such as protons, neutrons, and electrons.
• They have mass and occupy space, and their behavior is governed by principles of classical mechanics and quantum mechanics.
• Examples of particles include individual atoms of elements like hydrogen (H), molecules like water (H₂O), and ions like sodium ions (Na+) and chloride ions (Cl-).

Ions

• Ions are charged particles formed when atoms gain or lose electrons, resulting in an imbalance between the number of protons and electrons.
• Cations are positively charged ions formed when atoms lose electrons. For example, sodium ion (Na+) is formed when a sodium atom loses one electron.
• Anions are negatively charged ions formed when atoms gain electrons. For example, chloride ion (Cl-) is formed when a chlorine atom gains one electron.
• Ions play crucial roles in chemical reactions, electrolysis, and electrical conductivity in solutions. They are also essential for maintaining the balance of charges in biological systems and regulating cellular processes.

Radicals

• Radicals are highly reactive chemical species containing unpaired electrons. They are typically formed by the homolytic cleavage of chemical bonds, where each atom retains one electron from the bond.
• Radicals are represented with a dot to denote the unpaired electron. For example, the hydroxyl radical is represented as •OH.
• Due to the presence of unpaired electrons, radicals are extremely reactive and can participate in a wide range of chemical reactions, including oxidation-reduction reactions, radical polymerization, and atmospheric reactions.
• Examples of radicals include hydroxyl radical (•OH), methyl radical (•CH₃), and nitrogen dioxide radical (•NO₂).