Question

PLEASE HELP ASAP!!!

There are four isotopes of lead and their relative abundance listed below.  Use this information to calculate the approximate atomic mass of lead.  Show all work clearly!!  (4 points)

           82 protons, 122 neutrons, 1.4%

           82 protons, 125 neutrons, 22.1%

          82 protons, 124 neutrons, 24.1%

         82 protons, 126 neutrons, 52.4%

PLEASE SHOW WORK!!!

Answer 1

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

Step-by-step 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}* (\text{fractional abundance)})`

Average atomic mass of lead =

`(204 amu* 0.014+207 amu* 0.221 amu+206* 0.241+208 amu* 0.524)=207.24 amu`

The approximate atomic mass of lead is 207.24 amu.