An element consists of 1.40% of an isotope with mass 203.973 amu, 24.10% of an isotope with mass 205.9745 amu, 22.10% of an isotope with mass 207.9766 amu. Calculate the average atomic mass and identify the element
Those do not add up to 100% , typo?
By the way lead, Pb, is about 207.2
To calculate the average atomic mass of the element, we need to multiply the abundance of each isotope by its mass number and then sum these values.
Given:
Abundance of isotope 1 = 1.40%
Mass of isotope 1 = 203.973 amu
Abundance of isotope 2 = 24.10%
Mass of isotope 2 = 205.9745 amu
Abundance of isotope 3 = 22.10%
Mass of isotope 3 = 207.9766 amu
Step 1: Convert the abundance percentages to decimals by dividing by 100.
Abundance of isotope 1 = 1.40/100 = 0.0140
Abundance of isotope 2 = 24.10/100 = 0.2410
Abundance of isotope 3 = 22.10/100 = 0.2210
Step 2: Calculate the mass contribution of each isotope by multiplying its abundance by its mass.
Mass contribution of isotope 1 = 0.0140 * 203.973 = 2.855, rounded to three decimal places.
Mass contribution of isotope 2 = 0.2410 * 205.9745 = 49.626, rounded to three decimal places.
Mass contribution of isotope 3 = 0.2210 * 207.9766 = 45.953, rounded to three decimal places.
Step 3: Sum the mass contributions of all isotopes to get the average atomic mass.
Average atomic mass = mass contribution of isotope 1 + mass contribution of isotope 2 + mass contribution of isotope 3
Average atomic mass = 2.855 + 49.626 + 45.953 = 98.434 amu, rounded to three decimal places.
Therefore, the average atomic mass of the element is approximately 98.434 amu.
To identify the element, you would need to provide additional information such as the atomic number or name of the element. The average atomic mass alone does not uniquely identify an element.