Science Chapter 5 & 6 Study Guide

Science Study Guide

• This study guide may contain inaccuracies, inconsistencies, and omissions. Students should verify information independently.

Legend

• Red symbol = Important information
• Orange symbol = Important people

Contents

• GRASS: Steps in solving word problems

• Chemistry:

  • Chapter 5.1: Matter & energy, particle theory of matter, classifying matter (pure substances, mixtures, solutions, elements, compounds)
  • Chapter 5.2, 5.3, 5.6: Properties of matter, physical and chemical changes
  • Chapter 6.1, 6.4: Periodic table, first 20 elements (name and symbol), organization of the modern periodic table (by atomic number, metals, metalloids, non-metals, alkali metals, alkaline metals, halogens, noble gases), Mendeleev's periodic table
  • Chapter 6.6: Scientists (Democritus, Dalton, Thomson, Rutherford, Bohr) and their theories of the atom
  • Chapter 6.7: Atomic notation, atomic number

• Additional Information (Page 2): Mass number, Bohr-Rutherford model diagrams, reactivity of alkali metals

• GRASS (Steps in Solving Word Problems):

  • Given: Sketch, important facts, mathematical representation of these facts
  • Required: Question being asked, quantity to be calculated
  • Assemble: Formula relating given and required quantities
  • Substitute: Units for formulas, converting given units, values for formulas
  • Solve: Calculations, check, realism, number of digits in answer, concluding statement

• Matter & Energy:

  • Matter: Anything with mass and occupies space
  • Energy: Ability to do work, make things move, not like matter

• Properties or Characteristics:

  • Characteristics used to describe substances
  • Distinguishing characteristics: Color, quantity, quality, features, etc.

• The Particle Theory of Matter: (SPIASM)

  • Small Particles
  • Identical
  • Attractive
  • Stronger
  • Motion
  • Size of particles is small compared to space between particles
  • Particles move faster with higher temperature.

• States of Matter: Solids, liquids, gases

• Changes of State: Melting, evaporation, vaporization, temperature, energy of particles, motion, spaces, attraction between particles

• Classifying Matter:

  • Pure substances: Elements, compounds
  • Mixtures: Mechanical mixtures (heterogeneous mixtures), solutions (homogeneous mixtures) Alloy, Solute, solvent, Homogeneous, heterogeneous.

• Physical and Chemical Changes:

  • Physical change: Does not form a new substance
  • Reasons for a physical change: Change of state, dissolving, change of shape
  • Chemical change: Change that forms a new substance
  • Reasons for a chemical change: Unexpected color change, energy change (heat, light), gas bubbles, formation of a precipitate, difficulty reversing the change

• Density:

  • Definition: How much space an object or substance occupies
  • Formula: Density = mass/volume (d = m/V)

• Vanishing Substances (Solutions):

  • Definition: Substance dissolved in another substance to form a combined substance
  • Solute: Substance dissolves
  • Solvent: Substance that is doing the dissolving

• How Are Solutions Made?:

  • Solvent (e.g., water), solute (e.g., sugar)
  • Concentrated solutions: High solute concentration
  • Dilute solutions: Low solute concentration

• Properties of Matter: Qualitative properties (physical state, optical clarity, color, texture, luster, density, melting/freezing point, etc)

• Solubility: Ability to dissolve in another substance

• Hardness: Resistance to scratching

• Venn Diagram: Showing which properties are applied to solids, liquids, gases

• Periodic Table: Organization of elements, atomic number defines elements, first 20 elements listed

• Atomic Notation:

  • Mass number (A) = # of protons + # of neutrons
  • Atomic Number (Z) = # of protons = # of electrons (because atoms are neutral)

• Atomic Mass and Isotopes:

  • Atomic mass: Average mass of all naturally occurring isotopes of an element
  • Mass number: Number of protons and neutrons in an atom of an isotope.

• Bohr and Rutherford:

  • Bohr model: Electrons orbit in fixed energy levels around the nucleus
  • Rutherford model: Most of an atom's mass is in a small, positively charged nucleus

• Valence Electrons, Chemical Reactivity, and Ions

  • Valence electrons: Electrons in the outermost orbital
  • Chemical reactivity: Affected by valence electrons
  • Ions: Formed when atoms gain or lose electrons.

• Counting Atoms

  • Subscripts: Represent number of atoms of an element in a molecule, outside of parentheses multiplies the number of atoms inside
  • Coefficients: Represent number of molecules, multiplies all the atoms of each element in a formula

• History of the Periodic Table

• The Greek Philosophers: Democritus (Atoms), Aristotle (Four basic elements)

• Dalton Model: Atoms are tiny spheres, different elements are different in a reaction elements rearrange, atoms are not created or destroyed.

• Thomson Experiment: Discovery of the electron

• Rutherford Model: Discovery of the nucleus