Matter Notes

1. Matter

  • Definition: Matter is anything that has mass and occupies space (volume).

2. Classify Matter

  • Matter can be classified into Pure Substances and Mixtures:

    • Pure Substances: Can’t be separated into other types of matter by physical methods. They consist of either elements or compounds.

    • Mixtures: Consist of two or more substances that are physically combined and can be separated by physical means (e.g., filtration, distillation).

3. Identify a Solution/Aqueous Solution

  • Solution: A homogeneous mixture where one substance (solute) is dissolved in another (solvent).

  • Aqueous Solution: A solution in which water is the solvent.

4. Identify an Alloy

  • Alloy: A mixture of two or more metals, or a metal and a nonmetal, that has metallic properties. Example: Bronze (copper and tin).

5. Define Element, Identify Symbol

  • Element: A pure substance consisting of only one type of atom. Example: Oxygen (O), Hydrogen (H).

  • Symbol: A one- or two-letter abbreviation used to represent an element. Example: Carbon is represented by the symbol C.

6. Define Compound, Identify Formula

  • Compound: A substance made up of two or more different elements chemically bonded. Example: Water (H₂O), Sodium chloride (NaCl).

  • Formula: The chemical notation representing a compound’s elements and the ratio of their atoms. Example: H₂O for water, where 2 hydrogen atoms bond with 1 oxygen atom.

7. Distinguish Between Pure Substances and Mixtures

  • Pure Substances: Made up of only one type of matter, either an element or a compound.

  • Mixtures: Combinations of two or more pure substances that are physically mixed, not chemically bonded.

8. Distinguish Between Homogeneous and Heterogeneous

  • Homogeneous Mixture: A mixture in which the components are uniformly distributed. Example: Saltwater.

  • Heterogeneous Mixture: A mixture where the components are not uniformly distributed. Example: Sand and water.

9. Distinguish Between Qualitative and Quantitative Observations

  • Qualitative Observations: Descriptions that don’t involve numbers. Example: "The solution is clear."

  • Quantitative Observations: Observations that involve numbers or measurements. Example: "The solution has a temperature of 25°C."

10. Classify Physical Properties as Extensive or Intensive

  • Extensive Properties: Depend on the amount of matter present. Example: Mass, volume.

  • Intensive Properties: Do not depend on the amount of matter. Example: Density, boiling point.

11. Identify Physical and Chemical Properties

  • Physical Properties: Can be observed or measured without changing the substance’s composition. Example: Color, density, melting point.

  • Chemical Properties: Describe how a substance reacts to form a new substance. Example: Flammability, reactivity with acid.

12. Calculate Density

  • Formula for Density: Density=MassVolume\text{Density} = \frac{\text{Mass}}{\text{Volume}}

    • Example: If a substance has a mass of 10 grams and a volume of 5 cm³, its density is 10 g5 cm3=2 g/cm3\frac{10 \, \text{g}}{5 \, \text{cm}^3} = 2 \, \text{g/cm}^3.

13. Identify Physical and Chemical Changes

  • Physical Change: A change that affects the form of a substance, but not its chemical composition. Example: Melting ice.

  • Chemical Change: A change in which the substance becomes a new substance with different properties. Example: Burning paper.

14. Define Energy

  • Energy: The capacity to do work or produce heat. It exists in many forms, including kinetic, potential, thermal, and chemical energy.

15. Distinguish Between Endothermic and Exothermic

  • Endothermic: A reaction that absorbs heat from the surroundings. Example: Ice melting.

  • Exothermic: A reaction that releases heat to the surroundings. Example: Combustion of fuel.

16. Perform Calculations Involving Units of Energy Using Dimensional Analysis

  • Energy is often measured in joules (J), calories (cal), or kilocalories (kcal). Dimensional analysis involves converting units using conversion factors.

    • Example: Convert 1000 joules to calories. (1 cal = 4.184 J) 1000 J4.184 J/cal=239.0057 cal\frac{1000 \, \text{J}}{4.184 \, \text{J/cal}} = 239.0057 \, \text{cal}

17. Perform Heat Calculations

  • Heat can be calculated using the formula: q=m⋅c⋅ΔTq = m \cdot c \cdot \Delta T Where:

    • qq = heat energy (Joules)

    • mm = mass (grams)

    • cc = specific heat capacity (J/g°C)

    • ΔT\Delta T = change in temperature (°C)

18. Perform Calculations to the Right Number of Significant Figures

  • Significant Figures: Numbers that carry meaningful information in a measurement. When performing calculations, the result should be rounded to the correct number of significant figures based on the input values.

    • Example: In the calculation 2.50×3.02.50 \times 3.0, the result should have 2 significant figures because 3.0 has 2 significant figures, so the result should be rounded to 7.5.