Atomic Number and 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
• Why do atoms have no overall charge?

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

  The number of protons in an atom
• How many protons do lithium atoms have?

  Three protons
• What does the mass number indicate?

  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 typically have?

  Four neutrons
• What are the numbers of protons, neutrons, and electrons in atoms of bromine?

  • Protons: 35
  • Neutrons: 45
  • Electrons: 35
• What are the numbers of protons, neutrons, and electrons in atoms of sodium?

  • Protons: 11
  • Neutrons: 12
  • Electrons: 11
• What are the numbers of protons, neutrons, and electrons in atoms of fluorine?

  • Protons: 9
  • Neutrons: 10
  • Electrons: 9
• What are the numbers of protons, neutrons, and electrons in atoms of phosphorus?

  • Protons: 15
  • Neutrons: 16
  • Electrons: 15
• What is a key fact about atoms of the same element?

  They have the same number of protons
• What are isotopes?

  Atoms of the same element with different numbers of neutrons
• What are the three common isotopes of carbon?

  1. 6 protons, 6 neutrons
  2. 6 protons, 7 neutrons
  3. 6 protons, 8 neutrons
• How many protons and neutrons are in the first isotope of chlorine?

  17 protons and 18 neutrons
• How many protons and neutrons are in the second isotope of chlorine?

  17 protons and 20 neutrons
• What are ions?

  Atoms that have an overall charge due to lost or gained electrons
• What happens to positive ions?

  They have lost electrons
• What happens to negative ions?

  They have gained electrons
• How many protons, neutrons, and electrons does a sodium ion with a single positive charge have?

  11 protons, 12 neutrons, and 10 electrons
• How many protons, neutrons, and electrons does a fluoride ion with a single negative charge have?

  9 protons, 10 neutrons, and 10 electrons
• What are the numbers of protons, neutrons, and electrons in an oxide ion with a two negative charge?

  • Protons: 8
  • Neutrons: 8
  • Electrons: 10
• What are the numbers of protons, neutrons, and electrons in an aluminium ion with a three positive charge?

  • Protons: 13
  • Neutrons: 14
  • Electrons: 10
• Where can you find questions on this topic?

  In the vision workbook