Isotope Abundance and Average Atomic Mass in Elements

The video tutorial explains the concept of relative abundance, which is the percentage of each isotope in a naturally occurring sample of an element. It uses visual examples with colored dots to illustrate the concept. The tutorial then focuses on chlorine isotopes, explaining how to calculate the average atomic mass using their relative abundances. The formula involves multiplying the mass of each isotope by its percentage and summing the results. The video further applies this concept to uranium and silver isotopes, helping viewers understand which isotopes are more common based on average atomic mass.

What does relative abundance refer to in the context of isotopes?

• The total number of isotopes in an element

• The percentage of each isotope in a sample

• The mass of an isotope

• The color of isotopes in a sample

In the analogy using colored dots, what does a 50-50 distribution of red and yellow dots represent?

• No isotopes present

• More red isotopes

• Equal abundance of isotopes

• More yellow isotopes

What are the masses of chlorine-35 and chlorine-37 isotopes?

• 35 amu and 36 amu

• 37 amu and 39 amu

• 35 amu and 37 amu

• 34 amu and 36 amu

What is the relative abundance of chlorine-35?

• 50%

• 25%

• 75%

• 100%

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

• Add the masses of the isotopes

• Subtract the mass of one isotope from the other

• Multiply the mass of each isotope by its relative abundance and sum the results

• Divide the mass of each isotope by its relative abundance

What is the average atomic mass of chlorine when chlorine-35 and chlorine-37 are mixed?

• 34.5 amu

• 37.5 amu

• 35.5 amu

• 36.5 amu

Which uranium isotope is more common based on its average atomic mass of 238.03?

• Uranium-235

• Uranium-238

• Both are equally common

• Neither is common

If silver has an average atomic mass of 107.87, which isotope is more prevalent?

• Both are equally prevalent

• Silver-109

• Silver-107

• Neither is prevalent

What would the average atomic mass be if silver isotopes were equally abundant?

• 109 amu

• 110 amu

• 108 amu

• 107 amu

Why is understanding relative atomic mass important?

• It explains the atomic masses on the periodic table

• It is used to calculate the number of isotopes

• It helps in identifying the color of isotopes

• It determines the chemical properties of elements