Isotopes and Average Atomic Mass Insights

What does the term 'isotope' refer to?

• Elements with the same number of neutrons but different protons

• Elements with the same atomic number but different mass numbers

• Elements with different numbers of protons and neutrons

• Elements with the same mass number but different atomic numbers

Which of the following is true about hydrogen isotopes?

• They have different mass numbers

• They have the same number of neutrons

• They have different atomic numbers

• They have different numbers of protons

How many neutrons are present in carbon-14?

• 12

• 6

• 8

• 14

What is the mass number of an isotope with 8 protons and 9 neutrons?

• 15

• 17

• 9

• 8

Why isn't the atomic mass on the periodic table a whole number?

• It is the mass of the heaviest isotope

• It is the mass of the most abundant isotope

• It is an average of the masses of all isotopes of that element

• It is the sum of the protons and neutrons

How do you calculate the average atomic mass of an element?

• By calculating a weighted average of the masses of all isotopes

• By taking the mass of the most abundant isotope

• By dividing the total mass by the number of isotopes

• By adding the masses of all isotopes

What is the average atomic mass of boron if 19.78% of its isotopes have a mass of 10.013 amu and 80.22% have a mass of 11.009 amu?

• 10.013 amu

• 11.009 amu

• 10.82 amu

• 10.50 amu

If 93.1% of potassium isotopes have a mass of 38.964 amu and 6.88% have a mass of 40.962 amu, what is the average atomic mass?

• 38.964 amu

• 39.50 amu

• 40.962 amu

• 39.10 amu

Which of the following statements is true about weighted averages?

• They are calculated by simply adding all values and dividing by the number of values

• They take into account the relative abundance of each value

• They are always closer to the highest value

• They give equal importance to all values

What should you check to ensure your calculated average atomic mass is correct?

• It should be lower than the lowest isotope mass

• It should be equal to the most abundant isotope mass

• It should be higher than the highest isotope mass

• It should fall between the lowest and highest isotope masses