atomic + mass number

• What is the charge of electrons?

  Electrons have a negative charge.
• What particles are found in the nucleus of an atom?

  Protons and neutrons are found in the nucleus.
• Why do atoms have no overall charge?

  Because the number of electrons equals the number of protons.
• What does the atomic number represent?

  The atomic number represents the number of protons in an atom.
• How many protons do lithium atoms have?

  Lithium atoms have three protons.
• How many electrons do lithium atoms have?

  Lithium atoms have three electrons.
• What does the mass number indicate?

  The mass number indicates the total number of protons and neutrons in an atom.
• How do you calculate the number of neutrons in an atom?

  Subtract the atomic number from the mass number.
• How many neutrons do lithium atoms contain?

  Lithium atoms contain four neutrons.
• What is a key fact about atoms of the same element?

  All atoms of the same element have the same number of protons.
• What are isotopes?

  Isotopes are atoms of the same element with different numbers of neutrons.
• What are the common isotopes of carbon?

  1. 6 protons and 6 neutrons
  2. 6 protons and 7 neutrons
  3. 6 protons and 8 neutrons
• What are ions?

  Ions are atoms that have an overall charge due to lost or gained electrons.
• What happens to positive ions?

  Positive ions have lost electrons.
• What happens to negative ions?


  Negative ions have gained electrons.