relative formula mass

• What is the relative atomic mass of an element?

  It is the average mass of the isotopes of that element weighted by their abundance.
• What does the term 'abundance' refer to in the context of isotopes?

  Abundance refers to how common an isotope is.
• What is the atomic number of chlorine?

  The atomic number of chlorine is 17.
• How many neutrons does the chlorine isotope with mass number 35 have?

  It has 18 neutrons.
• How many neutrons does the chlorine isotope with mass number 37 have?

  It has 20 neutrons.
• What does the periodic table show about chlorine's mass number?

  The mass number of chlorine is 35.5, which is the average of its isotopes weighted by abundance.
• What is the definition of relative formula mass?

  The relative formula mass of a compound is the sum of the relative atomic masses of the atoms in the numbers shown in the formula.
• What symbol is used to represent relative formula mass?

  Relative formula mass has a specific symbol, often denoted as Mr.
• What are two key facts about relative formula mass?

  Relative formula mass has no units and never involves big numbers.
• How do you calculate the relative formula mass of methane (CH₄)?

  By adding 1 times the atomic mass of carbon (12) and 4 times the atomic mass of hydrogen (1), giving a total of 16.
• What is the relative formula mass of methane?

  The relative formula mass of methane is 16.
• What happens when a large number is placed in front of a formula, such as in 2CH₄?

  It indicates that there are two molecules of methane, but the relative formula mass remains the same at 16.
• What is the relative formula mass of calcium sulfate?

  The relative formula mass of calcium sulfate is 136.
• How do you calculate the relative formula mass of magnesium hydroxide (Mg(OH)₂)?

  By adding 1 times the atomic mass of magnesium (24), 2 times oxygen (16), and 2 times hydrogen (1), giving a total of 58.
• What is the relative formula mass of magnesium hydroxide?

  The relative formula mass of magnesium hydroxide is 58.
• What should you remember about relative formula mass regarding units?

  Relative formula mass has no units.
• What is the process for calculating relative formula mass?

  • Identify the atomic masses of each element in the formula.
  • Multiply the atomic mass by the number of atoms of that element.
  • Sum all the values to get the relative formula mass.