Chemistry Flashcards

Chemistry Basics

  • Chemistry is the study of matter's composition, properties, and changes.
  • Matter has mass and occupies space.
  • States of matter:
    • Solid: Definite shape and volume, rigid, incompressible.
    • Liquid: Definite volume, indefinite shape, incompressible.
    • Gas: Indefinite shape and volume, compressible.

Properties and Changes

  • Physical properties: Observed without changing the substance's identity (e.g., color, odor, melting/boiling points).
  • Chemical properties: Describe how a substance changes into a new substance (e.g., reactivity with oxygen).
  • Chemical change (reaction): Involves breaking down a substance into other substances.
    • Example: 2H<em>2O(l)→2H</em>2(g)+O2(g)2H<em>2O (l) \rightarrow 2H</em>2 (g) + O_2 (g)

Elements and Compounds

  • Element: A pure substance that cannot be broken down by ordinary chemical means (e.g., gold, copper).
  • Compound: A pure substance that can be broken down into simpler substances by chemical means (e.g., water, carbon dioxide).
  • Elements contain only one type of atom.
  • Compounds contain more than one type of atom in fixed ratios.

Names and Symbols

  • Chemical symbol: One- or two-letter notation for an element (first letter is uppercase, second is lowercase).

Metals and Nonmetals

  • Metals: Examples include gold, zinc, and copper.
  • Nonmetals: Poor conductors of heat and electricity; can be gases, solids, or liquid (bromine).

Measurements in Chemistry

  • Physical quantities: Measurable physical properties (e.g., height, volume, temperature).
  • Metric system: Based on factors of 10 (e.g., kg, meter, liter).
  • English system: U.S. customary units (e.g., miles, gallons, pounds).

Numbers in Science

  • Scientific notation: Used for very large or small numbers.
  • Prefixes: Used to represent powers of 10 (e.g., kilo-, milli-, micro-).

SI Base Units

  • Mass: Kilogram (kg)
  • Length: Meter (m)
  • Time: Second (s)
  • Temperature: Kelvin (K)
  • Amount of substance: Mole (mol)

Significant Figures

  • Rules for determining significant figures:
    • Nonzero digits are always significant.
    • Leading zeros are not significant.
    • Zeros between nonzero digits are significant.
    • Zeros at the end with a decimal point are significant.
    • Zeros at the end of the number with no decimal point are not significant
  • Rounding:
    • If the digit removed is 5 or greater, round up.
    • If the digit removed is less than 5, round down.
  • The answers contain the same number of significant figures as in the measurement with the fewest significant figures

Dimensional Analysis

  • Dimensional analysis: Converting units using conversion factors.
    • (starting quantity) x (conversion factor) = equivalent quantity

Density, Temperature, Heat

  • Density: Ratio of mass to volume (Density=massvolumeDensity = \frac{mass}{volume}).
    • Units: g/cm³ (solid), g/mL (liquid), g/L (gas).
  • Temperature: Measure of heat intensity.
  • Temperature Scales:
    • Kelvin: K=C+273.15K = C + 273.15
    • Celsius: C=59(F−32)C = \frac{5}{9}(F - 32)
    • Fahrenheit: F=1.8C+32F = 1.8C + 32