Atomic Structure

• What is the approximate radius of an atom?

  $1 \times 10^{-10} \text{ m}$
• How does the radius of the nucleus compare to the radius of the atom?

  The nucleus is less than 1/1000th the radius
• Why is the nucleus considered tiny compared to the atom?

  Because almost all mass is in the nucleus
• What two particles are found in the nucleus?

  Protons and neutrons
• What charge do protons have?

  Positive charge
• What charge do neutrons have?

  No charge
• What is the overall charge of the nucleus?

  Overall positive charge
• What charge do electrons have?

  Negative charge
• Where are electrons found in an atom?

  In energy levels around the nucleus
• How does the energy of an electron relate to its distance from the nucleus?

  Further electrons have higher energy levels
• What happens to an electron when it absorbs electromagnetic radiation?

  It moves from a lower to a higher energy level
• What occurs when an electron emits electromagnetic radiation?

  It returns to a lower energy level
• What is the relationship between electron arrangement and electromagnetic radiation?

  • Electrons can change energy levels
  • Absorption: moves to higher energy level
  • Emission: returns to lower energy level