Percent Abundance

Based on the mass spectrum, which isotope of chlorine is most abundant?

• ³⁵Cl

• ³⁷Cl

• ⁷⁰Cl

• ⁷²Cl

Rubidium has two common isotopes, ⁸⁵Rb and ⁸⁷Rb. If the abundance of ⁸⁵Rb is 72.2% and the abundance of ⁸⁷Rb is 27.8%, what is the average atomic mass of rubidium?

• 85.468 amu

• 37 amu

• 85.6 amu

• 86.4 amu

Which element does this mass spectrum most likely represent?

• neon

• scandium

• boron

• sodium

Tags

NGSS.HS-PS1-1

What is the percent abundance of Zinc-66?

• 48.89%

• 27.81%

• 4.11%

• 18.57%

Which isotope of Zinc has the lowest percent abundance?

• Zinc-64

• Zinc-66

• Zinc-67

• Zinc-70

What is the second step in determining the average atomic mass?

• Add up all the products of the fractional abundance and mass of the isotope

• Multiply the fractional abundance by the mass of the isotope

• Turn the percent abundance into a decimal number

• Find the mass on the periodic table

How many isotopes of Zinc are listed in the table?

• 3

• 4

• 5

• 6

If Carbon has two isotopes, Carbon-12 and Carbon-13, with percent abundances of 98.89% and 1.11% respectively, what is the first step to find the average atomic mass?

• Add the masses of Carbon-12 and Carbon-13

• Multiply the percent abundances by the masses of Carbon-12 and Carbon-13

• Convert the percent abundances to fractional abundances

• Find the mass of Carbon on the periodic table

What is the percent abundance of Carbon-13 in Example 2?

• 98.89%

• 1.11%

• 50%

• 100%

Find the average atomic mass of iodine if it consists of 80% iodine-127, 17% iodine-126, and 3% iodine-128.

• 126.7 amu

• 127.0 amu

• 126.9 amu

• 127.1 amu