Chapter 1: Matter, Measurement, and Problem Solving – General Chemistry Study Notes

Chapter 1: Matter, Measurement, and Problem Solving

Atoms and Molecules

Understanding the basic building blocks of matter is fundamental to chemistry. Atoms and molecules are the foundation of all substances in the universe.

• Atom: A submicroscopic particle that serves as the basic building block of all matter. Each atom consists of a nucleus (protons and neutrons) and electrons.

• Molecule: A group of two or more atoms chemically bonded together. Molecules can be composed of the same or different types of atoms.

• Examples:

  • Carbon monoxide (CO): Composed of one carbon atom and one oxygen atom.

  • Water (H2O): Composed of two hydrogen atoms and one oxygen atom.

  • Hydrogen peroxide (H2O2): Composed of two hydrogen atoms and two oxygen atoms.

  • Carbon dioxide (CO2): Composed of one carbon atom and two oxygen atoms.

Additional info: The arrangement and type of atoms in a molecule determine its chemical properties and behavior.

Carbon Monoxide – Toxicity and Biological Impact

Carbon monoxide (CO) is a toxic molecule that can have serious biological effects.

• Toxicity: CO binds to hemoglobin in red blood cells, preventing oxygen from binding and being transported throughout the body.

• Biological Impact: Exposure to CO can lead to oxygen deprivation in tissues, resulting in symptoms such as headache, dizziness, and even death in severe cases.

• Example: The molecular structure of CO allows it to fit into the same binding site on hemoglobin as oxygen, but with a much higher affinity.

DNA – Molecular Structure

DNA (deoxyribonucleic acid) is a complex molecule that carries genetic information in living organisms.

• Composition: DNA is made up of atoms such as hydrogen, oxygen, nitrogen, carbon, and phosphorus.

• Structure: DNA consists of two strands forming a double helix, with base pairs (adenine, thymine, cytosine, guanine) connected by hydrogen bonds.

• Example: The arrangement of atoms in DNA determines the genetic code and biological function.

Additional info: The molecular structure of DNA is an example of how chemistry underpins biological processes.

Chemistry – The Science of Matter

Chemistry is the scientific discipline that seeks to understand the behavior of matter by studying the behavior of atoms and molecules.

• Definition: Chemistry investigates the composition, structure, properties, and changes of matter.

• Key Principle: Different atoms, molecules, or arrangements of atoms result in different properties of substances.

• Example: Water (H2O) and hydrogen peroxide (H2O2) have different properties due to their molecular composition.

The Scientific Approach to Knowledge

The scientific method is a systematic approach used in chemistry to gain knowledge and understanding of natural phenomena.

• Hypothesis: A proposed explanation for observations. Hypotheses can be tested and refuted or confirmed by further experiments.

• Scientific Law (Principle): A statement that summarizes past observations and predicts future ones. Laws describe what happens but do not explain why.

• Scientific Theory: A model that explains what nature does and why. Theories provide the underlying reasons for laws and observations.

• Example: The Law of Conservation of Mass states that mass is conserved in a chemical reaction, while atomic theory explains why this is true.

Additional info: The scientific method involves observation, hypothesis formation, experimentation, and refinement of theories and laws.