Mass Spectrometry and Isotopes Concepts

This video tutorial covers the concept of average atomic mass and the role of isotopes in determining it. It explains isotopes as atoms with the same number of protons but different neutrons, using carbon and oxygen as examples. The video demonstrates how to calculate average atomic mass by multiplying the mass of each isotope by its natural abundance. It also introduces mass spectrometry, a technique used to determine the molecular mass of atoms or molecules, and explains how it helps identify isotopes and calculate average atomic mass.

What defines isotopes of an element?

• Same number of protons, different number of neutrons

• Same number of neutrons, different number of protons

• Same number of protons and neutrons

• Different number of electrons, same number of protons

How is the average atomic mass of an element determined?

• By summing the masses of isotopes and dividing by the number of isotopes

• By taking the mass of the most abundant isotope

• By averaging the mass numbers of all isotopes

• By multiplying the mass of each isotope by its natural abundance and summing the results

What is the natural abundance of carbon-12 in nature?

• 100%

• 98.89%

• 1.11%

• 50%

What is the average atomic mass of carbon?

• 12.00 amu

• 12.01 amu

• 13.00 amu

• 11.99 amu

Which isotope of oxygen is most abundant based on its average atomic mass?

• Oxygen-16

• Oxygen-17

• All isotopes are equally abundant

• Oxygen-18

What is the average atomic mass of oxygen?

• 15.999 amu

• 16.999 amu

• 17.999 amu

• 18.999 amu

What is mass spectrometry used for?

• Determining the color of elements

• Measuring the temperature of a sample

• Calculating the speed of atoms

• Determining the molecular mass of atoms or molecules

How does mass spectrometry separate ions?

• By their mass to charge ratio

• By their color

• By their speed

• By their temperature

What percentage of copper isotopes is copper-63 in a typical sample?

• 31%

• 50%

• 69%

• 100%

What is the purpose of using a mass spectrometer in the context of isotopes?

• To determine the color of isotopes

• To find the temperature of isotopes

• To identify the isotopic composition of a sample

• To measure the speed of isotopes