Atomic structure, isotopes, electron shells

• What is the central part of an atom called?

  Nucleus
• What particles are found in the nucleus of an atom?

  Protons and neutrons
• What is the charge of protons?

  Positive
• What is the charge of neutrons?

  Neutral
• What is the relative mass of protons and neutrons?

  One
• How much smaller are electrons compared to protons or neutrons?

  About 2000 times smaller
• What is the charge of electrons?

  Negative
• What does each box in the periodic table represent?

  A particular element
• What is the elemental symbol for lithium?

  Li
• What does the atomic number indicate?

  Number of protons in an atom
• Why is the atomic number important?

  It determines the element's identity
• What is the mass number?

  Total number of protons and neutrons
• What is the mass number of lithium?

  Seven
• How many electrons does lithium have?

  Three
• What are isotopes?

  Atoms with the same protons, different neutrons
• What is an example of an isotope of lithium?

  Lithium-6
• What happens to unstable isotopes?

  They decay into other elements
• What is radioactive decay?

  Process of unstable isotopes emitting radiation
• What are the types of radiation emitted during decay?

  Alpha, beta, and gamma radiation
• How are electrons arranged in an atom?

  In energy levels called shells
• What happens when an electron gains energy?

  It can jump to a higher energy level
• What is an excited electron?

  An electron in a higher energy level
• What provides the energy for an electron to jump levels?

  Electromagnetic radiation
• What happens after an electron falls back to a lower energy level?

  It re-emits energy as radiation
• What is ionization?

  When an electron leaves the atom
• What charge does an atom have after losing an electron?

  Positive charge
• What is an ion?

  An atom with a charge
• What does ionizing radiation do?

  Knocks electrons off atoms
• What is the main topic of the video?

  Review of the atom
• What are the key components of an atom?

  • Nucleus (protons and neutrons)
  • Electrons in shells
  • Atomic number (number of protons)
  • Mass number (total protons and neutrons)
• What is the process of electron excitation and return?

  1. Electron gains energy from electromagnetic radiation
  2. Jumps to a higher energy level (excited state)
  3. Falls back to lower energy level
  4. Re-emits energy as electromagnetic radiation
• What are the characteristics of isotopes?

  • Same number of protons (same atomic number)
  • Different number of neutrons
  • Different mass numbers
  • Generally, only one or two stable isotopes
• What is the significance of ionization in atoms?

  • Loss of an electron leads to a positive ion
  • Ionizing radiation can knock electrons off atoms
  • Important in chemical reactions and processes