Question

1. the weighted average of isotopes is closest to: *

a) the mass of the heaviest isotope
b) the mass of the lightest isotope
c) the isotope with the highest percent abundance
d) the difference between protons and neutrons

1. which of the following best describes why different isotopes of the same element have unique properties?

a) variations in proton count
b) variations in neutron count
c) variations in electron configuration
d) variations in atomic weight
15 in radiometric dating, the half - life represents

Explanation:

1. The weighted - average of isotopes is calculated based on the mass and abundance of each isotope. The isotope with the highest percent abundance has the greatest influence on the weighted - average, so the weighted average is closest to its mass.
2. Isotopes of the same element have the same number of protons but different numbers of neutrons. Variations in neutron count lead to unique properties.
3. In radiometric dating, the half - life is defined as the time required for half of the parent isotope to decay into daughter isotopes.

Answer:

1. c) The isotope with the highest percent abundance
2. B) Variations in neutron count
3. B) The time required for half of the parent isotope to decay into daughter isotopes