Question

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Answer 1

Answer:The approximate atomic mass of lead is 207.24 amu.

Explanation:

Abundance of isotope (I) = 1.4% = 0.014

Atomic mass of the Isotope (I) = number protons +  number of neutrons = 82 + 122 = 204 amu

Abundance of isotope (II) = 22.1 % = 0.221

Atomic mass of the Isotope (II) = number protons +  number of neutrons = 82 + 125 = 207 amu

Abundance of isotope (III) = 24.1% = 0.241

Atomic mass of the Isotope (III) = number protons +  number of neutrons = 82 + 124 = 206 amu

Abundance of isotope (IV) = 52.4% = 0.524

Atomic mass of the Isotope (IV) = number protons +  number of neutrons = 82 + 126 = 208 amu

Average atomic mass of an element =

$\sum(\text{atomic mass of an isotopes}\times (\text{fractional abundance)})$

Average atomic mass of lead =

$(204 amu\times 0.014+207 amu\times 0.221 amu+206\times 0.241+208 amu\times 0.524)=207.24 amu$

The approximate atomic mass of lead is 207.24 amu.