Lecture on Chemistry for Biology Students

Importance of Chemistry in Biology

• Biology involves understanding living systems, which are chemical systems.
• Example: Humans ingest food (chemical substances), break it down (digestion), and use it in cellular functions.
• Chemistry is fundamental to life processes.

Introduction to Atoms

• Atoms: Building blocks of matter, extremely small.
  • Example: Carbon atom radius is 70 trillionths of a meter.
• Mass concentrated in the nucleus.
  • Nucleus: Contains protons (positive charge) and neutrons (no charge).
• Electrons: Negatively charged, orbit the nucleus.

Concept of Charge

• Fundamental property of certain particles.
  • Protons: Positive charge.
  • Electrons: Negative charge.
  • Neutrons: No charge.
• Like charges repel; unlike charges attract.

Atomic Structure and Elements

• Atom model: Miniature solar system.
  • Nucleus = sun; Electrons = orbiting planets.
• Electron regions: Called orbitals, energy levels, or shells.
• Uncharged atom: Equal number of protons and electrons.
• Neutron number can vary.
• Atoms with the same number of protons are the same element.
  • Examples: Oxygen, Iron, Carbon.

Elements and Periodic Table

• About 90 natural elements; additional elements created in laboratories.
• Each element has a chemical symbol (e.g., H for Hydrogen).
• Some symbols not derived from English (e.g., Na for Sodium).

Periodic Table Organization

• Elements organized by the number of protons and chemical properties.
• Atomic Number: Number of protons.
• Atomic Weight: Sum of protons, electrons, and average number of neutrons.
• Horizontal rows: Increase in proton number from left to right.
• Vertical columns (families): Elements with similar chemical properties.
  • Example: Lithium and Sodium are reactive metals.

Key Elements for Biology

• Biology focuses on approximately a dozen elements.
• Future lessons will cover these elements in more detail.

Learning and Interaction

• Importance of interaction with material for learning.
• Encourage visiting the website for interactive learning tools: sciencemusicvideos.com
  • Flashcards, quizzes, other activities.
• Active engagement is crucial for understanding and retention.