Atomic Structure

• Where is most of the mass of an atom concentrated?


  Almost all of the mass of the atom is concentrated in the nucleus.
• What two types of particles are found in the nucleus of an atom?

  Protons and neutrons.
• What charge do protons have, and what charge do neutrons have?


  Protons have a positive charge, and neutrons have no charge.
• What is the overall charge of the nucleus, and why?


  The nucleus has an overall positive charge due to the presence of protons.
• What charge do electrons have?


  Electrons have a negative charge.
• Where are electrons found in relation to the nucleus?


  Electrons are found in energy levels surrounding the nucleus.
• How does the energy of an electron relate to its distance from the nucleus?


  Energy levels further from the nucleus are at a higher energy than those closer to the nucleus.
• What happens to an electron when it absorbs electromagnetic radiation?


  The electron can move from a lower energy level to a higher energy level.
• What occurs when an electron emits electromagnetic radiation?


  The electron returns to a lower energy level from a higher energy level.
• What are the key points about the structure of an atom?


  • Atoms are very small, with a radius of about \(1 \times 10^{-10} \, \text{m}\).
  • The nucleus is tiny compared to the atom and contains protons and neutrons.
  • Protons have a positive charge, neutrons are neutral, and electrons have a negative charge.
  • Electrons are found in energy levels at varying distances from the nucleus.
  • Energy levels further from the nucleus have higher energy.
  • Electrons can change energy levels by absorbing or emitting electromagnetic radiation.