Fundamental Particles, Mass Number and Atomic Number

• What are the three fundamental subatomic particles of an atom?

  Protons, neutrons, and electrons
• What are protons and neutrons collectively called?

  Nucleons
• Where are protons and neutrons located in an atom?

  In the atom's nucleus
• What charge do protons have?

  Positive charge
• What charge do neutrons have?

  Electrically neutral
• What does the nucleus of an atom contain?

  The majority of an atom's mass
• How do electrons behave in relation to the nucleus?

  They orbit the nucleus in shells
• What is the volume of an atom mostly composed of?

  Empty space
• What is the relative mass of a proton?

  1
• What is the relative charge of an electron?

  • 1
• What do nuclear symbols represent in an atom?

  • Mass number (A): Total nucleons (protons + neutrons)
  • Atomic number (Z): Number of protons
• How do you determine the number of protons in a neutral atom?

  It equals the atomic number (Z)
• In a neutral atom, how do the number of electrons compare to protons?

  They are equal
• How do you calculate the number of neutrons in an atom?

  Mass number (A) - Atomic number (Z)
• How can you determine the number of protons, electrons, and neutrons in various neutral atoms using nuclear symbols?

  • Use atomic number (Z) for protons
  • In neutral atoms, electrons = protons
  • Neutrons = mass number (A) - atomic number (Z)
• What defines an ion?

  An atom with gained or lost electrons
• What are negative ions called?

  Anions
• How do negative ions differ from positive ions?

  Negative ions have more electrons than protons
• What are positive ions called?

  Cations
• If a particle has 1 proton and 2 electrons, what type of ion is it?

  Negative ion with charge -1
• If a particle has 3 protons and 2 electrons, what type of ion is it?

  Positive ion with charge +1