Nucleon and Proton Number

• What does the notation AZX represent?

  A nucleus description using nucleon and proton numbers

  
• What does the top number A in AX notation represent?

  The nucleon number or mass number
• How is the nucleon number (A) defined?

  Total number of protons and neutrons in the nucleus
• What does the lower number Z in AX notation represent?

  The proton or atomic number

  
• How is the proton number (Z) defined?

  Total number of protons in the nucleus
• What defines an element?

  A fixed number of protons in its atoms
• How many protons do all hydrogen atoms have?

  1 proton
• How many protons do all carbon atoms have?

  6 protons
• What is the relationship between nucleon number and isotopes?

  Isotopes have the same proton number but different nucleon numbers
• What are isotopes defined as?

  Nuclei with the same number of protons but different neutrons

  
• What are the two isotopes of hydrogen?

  Deuterium and tritium

  
• How does the nucleon number A relate to isotopes?

  An isotope has a different nucleon number A
• What happens to some isotopes with an imbalance of neutrons and protons?

  They become unstable and emit radiation
• What is isotopic data defined as?

  The relative amounts of different isotopes in a substance
• How is the relative atomic mass of an element calculated?

  Using the relative abundance values of isotopes
• How can the percentage abundance of isotopes in a sample be obtained?

  Using a mass spectrometer
• What isotopes are present in a sample of oxygen?

  ^{16}O, \, ^{17}O, \, ^{18}O

  
• How is the relative atomic mass of a sample of oxygen calculated?

  ($16 \times 0.9976$) + ($17 \times 0.0004$) + ($18 \times 0.002$)
• What is the relative atomic mass of the sample of oxygen to two decimal places?

  16.00
• What is a common use of isotopic data?

  Carbon dating of archaeological artifacts
• How is the age of a sample of dead tissue determined?

  By comparing isotope ratios with living tissue
• What are the properties of isotopes?

  • Same number of protons
  • Different number of neutrons
  • Different nucleon numbers

  
• How do you calculate the number of protons in a nucleus?

  Protons = Nucleon number - Neutrons