CHE 111 General Chemistry I – Study Guide: Matter, Measurement, and Atomic Theory

Unit 1: Matter and Measurement

1.1 Essential Ideas

This section introduces the foundational concepts of chemistry, including the scientific method, classification of matter, and the importance of measurement and precision in scientific investigations.

• Scientific Method: A systematic approach to investigation involving observation, hypothesis formation, experimentation, and conclusion.

• Classification of Matter: Matter can be classified as pure substances (elements and compounds) or mixtures (homogeneous and heterogeneous).

• Physical and Chemical Properties: Physical properties can be observed without changing the substance's identity (e.g., melting point, density), while chemical properties describe a substance's ability to undergo chemical changes.

• Measurement and Uncertainty: All measurements have some degree of uncertainty, which is expressed using significant figures.

• Accuracy and Precision: Accuracy refers to how close a measurement is to the true value, while precision refers to the reproducibility of measurements.

1.2 Chemistry in Context

• Understanding the role of chemistry in everyday life and its applications in various fields.

1.3 Phases and Classification of Matter

• States of Matter: Solid, liquid, and gas, each with distinct properties.

• Classification: Elements, compounds, and mixtures.

1.4 Measurement and Significant Figures

• Use of significant figures to reflect the precision of measurements.

• Rules for determining the number of significant figures in a measurement.

1.5 Mathematical Treatment of Measurement Results

• Performing calculations with measured values, maintaining correct significant figures.

• Use of scientific notation for very large or small numbers.

Appendix A: Units and Conversion Factors; Using Calculators

• Understanding and converting between different units of measurement (SI units).

• Using dimensional analysis to solve problems.

Key Equations and Constants

• Temperature conversions:

  • $^\circ F = ( ^\circ C \times \frac{9}{5}) + 32$

  • $^\circ C = ( ^\circ F - 32) \times \frac{5}{9}$

  • $K = ^\circ C + 273.15$

Unit 2: Elements, Atoms, and the Laws of Chemical Combination

2.1 Early Ideas of Atomic Theory

This section covers the historical development of atomic theory, including the contributions of early scientists and the evolution of the concept of the atom.

• Atomic Theory: The idea that matter is composed of discrete units called atoms.

2.2 Evolution of Atomic Theory

• Development of the modern atomic model, including the discovery of subatomic particles (protons, neutrons, electrons).

2.3 Atomic Structure and Symbolism

• Atomic Number (Z): Number of protons in the nucleus of an atom.

• Mass Number (A): Total number of protons and neutrons in the nucleus.

• Isotopes: Atoms of the same element with different numbers of neutrons.

• Atomic Symbols: Notation representing the element, atomic number, and mass number (e.g., $^{12}_{6}C$).

2.4 Chemical Formulas (Molecular and Empirical Formulas, Moles, Molar Mass)

• Molecular Formula: Shows the actual number of atoms of each element in a molecule.

• Empirical Formula: Shows the simplest whole-number ratio of atoms in a compound.

• Mole: The SI unit for amount of substance; 1 mole = $6.022 \times 10^{23}$ entities (Avogadro's number).

• Molar Mass: The mass of one mole of a substance, expressed in grams per mole (g/mol).

2.5 The Periodic Table

• Organization of elements by increasing atomic number.

• Groups (columns) and periods (rows) indicate elements with similar properties.

• Main group elements, transition metals, and inner transition metals.

• Metals, nonmetals, and metalloids: classification based on physical and chemical properties.

Key Equations and Constants

• Avogadro's Number: $6.022 \times 10^{23}$

Table: Classification of Matter

Type	Description	Examples
Element	Pure substance consisting of one type of atom	O2, Fe
Compound	Pure substance consisting of two or more elements chemically combined	H2O, NaCl
Homogeneous Mixture	Uniform composition throughout	Saltwater, air
Heterogeneous Mixture	Non-uniform composition	Salad, sand and water

Additional info:

• Students should be able to use dimensional analysis for unit conversions and problem-solving.

• Understanding the difference between accuracy and precision is essential for laboratory work.

• Knowledge of the periodic table's structure aids in predicting element properties and chemical behavior.