Explain of each:
Classification of Matter:
Matter can be classified into two main categories: pure substances and mixtures.
1. Pure Substances:
- Elements: These are substances that cannot be broken down into simpler substances by chemical means. Examples include hydrogen, oxygen, and gold.
- Compounds: These are substances that are composed of two or more elements chemically combined in fixed proportions. Compounds have unique chemical and physical properties different from their constituent elements. Examples include water (H2O) and table salt (NaCl).
2. Mixtures:
- Homogeneous Mixtures: These are mixtures in which the components are evenly distributed throughout and have the same composition and properties in any given sample. Examples include saltwater and air.
- Heterogeneous Mixtures: These are mixtures in which the components are not evenly distributed and have different compositions and properties in different parts of the mixture. Examples include salad dressing and soil.
Changes in Matter:
Matter can undergo various changes, which can be classified into two main categories: physical changes and chemical changes.
1. Physical Changes:
- Changes in State: Matter can change from one state to another (solid, liquid, gas) by altering temperature or pressure. Examples include melting of ice, boiling of water, and condensation of steam.
- Changes in Size and Shape: Matter can be physically modified without changing its chemical composition. Examples include cutting paper, stretching rubber, and crushing an aluminum can.
2. Chemical Changes (Chemical Reactions):
- Formation of New Substances: Matter can undergo chemical reactions that result in the formation of new substances with different chemical properties. Examples include burning wood, rusting of iron, and fermentation of sugars.
- Release or Absorption of Energy: Chemical reactions often involve the release or absorption of energy in the form of heat, light, or sound. Examples include combustion reactions (burning) and photosynthesis.
It's important to note that these classifications and changes in matter are fundamental concepts in chemistry and are used to understand the behavior and interactions of different substances.