Understanding Isotopes and Weighted Averages

What is the atomic number of copper isotopes discussed in the video?

• 31

• 30

• 29

• 28

How many protons and neutrons are there in the copper isotope with a mass number of 63?

• 63 protons only

• 65 protons and neutrons

• 65 protons only

• 63 protons and neutrons

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

• Add the mass numbers of the isotopes

• Subtract the smaller mass number from the larger one

• Multiply each mass number by its relative abundance

• Divide the total mass by the number of isotopes

Why is the calculated average atomic mass of copper closer to 63 than 65?

• Because there is a higher relative abundance of the isotope with mass number 63

• Because 63 is the atomic number

• Because 63 is a smaller number

• Because 65 is not a stable isotope

How can the method of calculating average atomic mass be applied to elements with more than two isotopes?

• By using the same weighted average method for all isotopes

• By ignoring isotopes with less than 10% abundance

• By adding the mass numbers of all isotopes and dividing by the number of isotopes

• By only considering the two most abundant isotopes