Fundamentals of Atomic Structure and Periodic Trends

📋 Course Outline

1. Atomic number and charge
2. Electrons and protons balance
3. Ion formation and charges
4. Atomic mass and neutrons
5. Isotopes and molar mass
6. Energy levels and orbitals
7. Electron configurations
8. Valence electrons and shells
9. Periodic table organization

📖 1. Atomic number and charge

🔑 Key Concepts & Definitions

• Atomic number: The number of protons in an atom’s nucleus. It is a fundamental identifier for each element. (source content)
• Charge on the nucleus: The positive charge of the nucleus, which always equals the atomic number. It is determined by the number of protons. (source content)
• Atomic symbol: A notation that includes the element’s symbol, often with atomic number and atomic mass shown as super/subscript numbers. (source content)

📝 Essential Points

• The atomic number equals the number of protons in the nucleus. For example, sodium (Na) has an atomic number of 11, meaning it has 11 protons.
• The charge on the nucleus is always positive and equals the atomic number. This positive charge is due to the protons.
• Each element is uniquely identified by its atomic number; any atom with the same atomic number belongs to that element.

💡 Key Takeaway

Understanding the atomic number as the fundamental identifier of an element reveals its direct relationship to the nucleus’s positive charge, which is always equal to the number of protons.