Calculating Atomic Mass of Gallium

The video tutorial explains how to calculate the average atomic mass of an element using isotopes. It uses gallium as an example, detailing its isotopes and their abundances. The instructor demonstrates the calculation process, emphasizing the use of weighted averages. The tutorial concludes by relating the calculation to the atomic masses listed on the periodic table.

Why is it beneficial to use examples when explaining the calculation of atomic mass?

• Examples make the process more complex.

• Examples help in visualizing the concept better.

• Examples are only useful for advanced learners.

• Examples are not necessary for understanding.

What are the masses of the two isotopes of gallium mentioned?

• 60.16 amu and 39.84 amu

• 68.95 amu and 69.95 amu

• 69.75 amu and 70.75 amu

• 68.95 amu and 70.95 amu

What is the significance of the percent abundances of isotopes?

• They determine the color of the element.

• They indicate the stability of isotopes.

• They are used to calculate the weighted average.

• They are irrelevant to atomic mass.

How is the weighted average used in calculating atomic mass?

• By adding the masses of isotopes directly.

• By multiplying each isotope's mass by its percent abundance.

• By subtracting the lighter isotope's mass from the heavier one.

• By dividing the total mass by the number of isotopes.

What is the first step in calculating the average atomic mass of gallium?

• Multiplying the mass of each isotope by its percent abundance.

• Adding the masses of the isotopes.

• Subtracting the percent abundances.

• Dividing the total mass by the number of isotopes.

What is the contribution of the first isotope to the atomic mass of gallium?

• 69.75 amu

• 28.27 amu

• 41.48 amu

• 70.95 amu

What is the final calculated average atomic mass of gallium?

• 68.95 amu

• 70.95 amu

• 69.75 amu

• 60.16 amu

What unit is used for atomic mass in this calculation?

• Atomic Mass Unit (amu)

• Kilograms

• Grams

• Moles

How are the atomic masses on the periodic table calculated?

• By counting the number of protons.

• By measuring the volume of elements.

• By using the weighted average of isotopes.

• By averaging the masses of all elements.

What should you do if an element has more than two isotopes?

• Ignore the additional isotopes.

• Only consider the heaviest isotope.

• Add more terms to the calculation for each isotope.

• Use only the lightest isotope for calculations.