introduction to matter and Pure Substance-.pptx

short intorduction to matter

1. Introduction to Matter and Pure Substances Understanding the Fundamental Building Blocks of Our World

2. What is Matter ? Definition: Anything that has mass and occupies space. Matter is fundamental to the universe, comprising all physical objects. Mixtures Pure Substances Composed of two or more substances. Can be separated physically. Composed of only one kind of particle. Possesses a fixed chemical composition. Pure Substances: Elements vs. Compounds FEATURE ELEMENTS (Cannot be broken down) COMPOUNDS (Can be broken down chemically) Two or more types of atoms chemically bonded Properties differ from constituent elements Composition Properties Examples Only one type of atom Retain their own unique properties Gold (Au), Oxygen (O₂), Hydrogen (H) Water (H₂O), Salt (NaCl), Carbon Dioxide (CO₂)

3. Properties of Pure Substances Fixed Chemical Composition Unique atomic or molecular arrangement defines properties. Definite Properties Consistent melting/boiling points Characteristic density Cannot be separated by physical means. Composition is constant Independent of source or amount Uniform structure throughout Predictable reactivity/flammability Melting Point: 0°C Boiling Point: 100°C Density: 1.0 g/cm³ Water (H₂O) Water (H₂O) Water (H₂O) at 4°C Elements Compounds "Single type of atom." "Two+ elements chemically bonded." "Properties distinct from constituents." Examples: Water (H₂O), Salt (NaCl) "Cannot be broken down chemically." Examples: Gold (Au), Oxygen (O₂)

4. Exploring Elements Definition of an Element Atomic Structure Connection A pure substance made up of only one kind of atom. An element's identity is defined by its unique atomic number. Identical properties throughout Key Characteristics Cannot be chemically broken down. Atomic Number (Z) = Number of Protons Represented by unique chemical symbols (e.g., H, O, Na, Fe). Protons: The defining factor Elements vs. Compounds: Distinct Entities Feature Elements Compounds Composition Separability Example Single atom type Multiple atom types, chemically bonded Chemically separable Not chemically separable Gold (Au), Oxygen (O 2 ) Water (H 2 O), Salt (NaCl)

5. Understanding Compounds Fixed Composition Definition Compounds strictly maintain a constant atomic ratio , crucial for their predictable Pure substances formed when two or more elements combine chemically in a fixed ratio, creating entirely new materials. behavior and identity. Characteristics Source: Britannica Properties significantly differ from their Common Compounds constituent elements. Represented by unique chemical formulas (e.g., Water (H₂O): 2 Hydrogen : 1 Oxygen H₂O, CO₂, NaCl). Carbon Dioxide (CO₂): 1 Carbon : 2 Oxygen Sodium Chloride (NaCl): 1 Sodium : 1 Chlorine

6. Elements vs. Compounds: A Comparison Elements Compounds Composition: One type of atom Composition: Two or more types of atoms Separation: Can be broken down chemically Representation: Chemical Formula (e.g., H₂O, NaCl) Ratio: Fixed ratio of elements Separation: Cannot be broken down chemically Representation: Chemical Symbol (e.g., O, Na) Ratio: N/A (single atomic unit) Pure substances, whether elements or compounds, possess a constant composition and identical properties throughout any given sample. Source: Pure Substance - Definition, Examples, Properties and Characteristics