Mixtures
* Definition: A combination of two or more substances that are not chemically bonded. Each substance retains its own properties.
* Components: Mixtures can be composed of:
* Elements: Pure substances that cannot be broken down further by chemical means (e.g., gold, oxygen).
* Compounds: Substances formed by the chemical combination of two or more elements in a fixed ratio (e.g., water, salt).
* Other mixtures: Mixtures can even be made of other mixtures!
Examples of Mixtures:
* Salt water: Salt (a compound) dissolved in water (a compound).
* Air: A mixture of gases like nitrogen, oxygen, carbon dioxide (all elements).
* Sand and water: A mixture of sand (a mixture of minerals) and water (a compound).
Key Characteristics of Mixtures:
* Components can be separated by physical means (filtration, evaporation, etc.).
* The proportions of components can vary.
* The properties of the mixture are often a blend of the properties of its components.
Elements
* Definition: Pure substances that cannot be broken down into simpler substances by ordinary chemical means.
* Components: Elements are made up of only one type of atom.
* Examples: Gold (Au), Oxygen (O), Carbon (C), Hydrogen (H).
Key Characteristics of Elements:
* Found on the periodic table.
* Cannot be broken down further.
* Have unique chemical and physical properties.
Compounds
* Definition: Substances formed when two or more elements chemically combine in a fixed ratio.
* Components: Compounds are made up of two or more different types of atoms chemically bonded together.
* Examples: Water (H₂O), Carbon dioxide (CO₂), Table salt (NaCl).
Key Characteristics of Compounds:
* Have properties different from the elements that make them up.
* Have a fixed ratio of elements (e.g., always two hydrogen atoms and one oxygen atom in water).
* Can only be broken down into their elements by chemical reactions.
In Summary:
* Mixtures: Combine substances without changing their chemical identities.
* Elements: The fundamental building blocks of matter, made of a single type of atom.
* Compounds: Form through chemical bonding between elements, creating new substances with unique properties.
