Separation of Mixtures and Matter Classification

Separation of Mixtures

• Mixtures are combinations of two or more substances that are not chemically combined.
• Compounds are substances formed when two or more elements combine chemically.
• Mixtures can be separated using various methods depending on the properties of the components.
• Suitable separation methods include:
  • Immiscible liquids: Separating liquids that don't mix (e.g., oil and water).
  • Magnetic properties: Separating a component with magnetic properties from a mixture.
  • Different sized solids: Sifting or using a sieve to separate substances of different sizes.
• Matter is classified into elements, compounds, and mixtures.

Elements, Compounds, and Mixtures

• The periodic table lists all known elements.
• The atom is the fundamental unit of an element, represented using symbols and atomic numbers.
• Atomicity refers to the number of atoms in a molecule of an element.
• Molecules are groups of atoms bonded together.
• Elements differ from compounds according to their composition.
  • Compounds are chemical combinations of multiple elements.

Air

• Deep-sea divers need oxygen cylinders because the water pressure at depth makes breathing air difficult.
• Plants utilize nitrogen from the air.
• The nitrogen and oxygen ratio in the atmosphere is important for life processes.
• Respiration produces carbon dioxide and water as by-products; considered an oxidation reaction.
• Air has mass.
• Carbon dioxide contributes to global warming in the atmosphere.
• Some particles in the atmosphere cause pollution.
• Water vapor in the atmosphere has utility, and its presence is important.
• Air composition is not fixed due to various factors (e.g., respiration and combustion).
• Air is important for soil health.
• The carbon dioxide-oxygen balance in the atmosphere is maintained through natural processes.