Isotopes

• What do atoms consist of?

  Atoms consist of a nucleus containing protons and neutrons, surrounded by electrons in shells.
• How can the numbers of subatomic particles in an atom be calculated?

  The numbers of subatomic particles can be calculated from its atomic number and mass number.
• What is the smallest part of an element that can exist?

  Atoms are the smallest part of an element that can exist.
• What is a proton?

  A proton is a subatomic particle with a positive charge and a relative mass of 1.
• What is a neutron?

  A neutron is an uncharged subatomic particle with a mass of 1 relative to a proton.
• What are isotopes?

  Isotopes are atoms of the same element with different numbers of neutrons.
• What do isotopes of an element have in common?

  Isotopes of an element have the same atomic number.
• What is the mass number?

  The mass number is the number of protons and neutrons found in the nucleus of an atom.
• How is an isotope named?

  An isotope is named after the element and the mass number of its atoms.
• What is the most abundant isotope of hydrogen?

  Hydrogen-1 is the most abundant isotope of hydrogen.
• What are the three isotopes of hydrogen and their characteristics?

  • Hydrogen-1 \(_{1}^{1}\textrm{H}\): 1 proton, 1 electron, 0 neutrons
  • Hydrogen-2 \(_{1}^{2}\textrm{H}\): 1 proton, 1 electron, 1 neutron
  • Hydrogen-3 \(_{1}^{3}\textrm{H}\): 1 proton, 1 electron, 2 neutrons
• Why do all isotopes of hydrogen have identical chemical properties?

  They have identical chemical properties because they all have one electron in their atoms.
• What is the relative atomic mass of an element?

  The relative atomic mass is a weighted average of the masses of the atoms of the isotopes.
• What does the relative atomic mass take into account?

  It takes account of the abundance of each of the isotopes of the element.
• What symbol is used for relative atomic mass?

  The symbol for relative atomic mass is \( A_r \).
• How do mass numbers and relative atomic masses differ?

  Mass numbers are always whole numbers, while relative atomic masses are often rounded but not whole numbers.
• What is an example of a relative atomic mass?

  The relative atomic mass of chlorine is 35.5.
• What isotopes does chlorine contain?

  • Chlorine-35
  • Chlorine-37