⚗️

Chemistry — Stream SA

Atomic structure, periodic table, chemical bonding, and basic reactions for Class 11

Key Concepts
  • Atomic structure and quantum numbers
  • Mole concept and stoichiometry
  • Periodic trends in the elements
  • Basics of chemical bonding
Important Formulae
Number of moles n = m/M
Ideal gas law PV = nRT
Max electrons in a shell 2n²
Quick Tips
  • Balance every equation before doing stoichiometry.
  • Learn periodic trends as patterns, not isolated facts.
Sample Practice Questions

  1. The most abundant gas in the Earth's atmosphere is:

    • Oxygen
    • Nitrogen
    • Carbon dioxide
    • Hydrogen
    Show answer

    Answer: Nitrogen

  2. An acidic solution has a pH that is:

    • Less than 7
    • Equal to 7
    • Greater than 7
    • Equal to 14
    Show answer

    Answer: Less than 7

  3. Avogadro's number is approximately:

    • 6.022×10²³
    • 3.0×10⁸
    • 1.6×10⁻¹⁹
    • 9.8
    Show answer

    Answer: 6.022×10²³

  4. The atomic number of an element equals the number of:

    • Neutrons
    • Protons
    • Electrons and neutrons
    • Nucleons
    Show answer

    Answer: Protons

Practise more questions →
Practice Questions

Practise KVPY questions on Chemistry — Stream SA. Answers are revealed after each question.

Start Practice →
Chemistry