Percent Abundance

Titanium has five common isotopes with the percent of abundance listed as follows: Titanium-46 (8.0%), Titanium-47 (7.8%), Titanium-48 (73.4%), Titanium-49 (5.5%), and Titanium-50 (5.3%). What is the average atomic mass of titanium?

• 47.87 amu

• 48.01 amu

• 47.90 amu

• 48.05 amu

Oxygen has 3 isotopes: Oxygen-16 with a percent abundance of 99.759%, Oxygen-17 with a percent abundance of 0.037%, and Oxygen-18 with a percent abundance of 0.204%. Calculate its average atomic mass.

• 16.00 amu

• 16.01 amu

• 16.02 amu

• 16.03 amu

Find the average atomic mass of sulfur if 95.00% is 32S, 0.76% is 33S, 4.22% is 34S, and 0.014% is 36S.

• 32.07 amu

• 32.06 amu

• 32.08 amu

• 32.09 amu

4.35% of all X atoms have a mass of 39.946 amu. 83.79% have a mass of 41.941 amu, 9.50% have a mass of 42.941 amu, and 2.36% have a mass of 43.939 amu. What is the average atomic mass of atom X?

• 41.97 amu

• 42.19 amu

• 10.43 amu

• 40.04 amu

An element has two naturally occurring isotopes. One is 10.013 amu and is 19.9% abundant. The other is 11.01 amu and is 80.1% abundant. What is the average atomic mass? What element is it?

• 9.012, Beryllium

• 12.011, Carbon

• 6.941, Lithium

• 10.812, Boron

Tags

NGSS.MS-PS1-1

Compute the average atomic mass for silicon:

• 27.977

• 28.09

• 28.976

• The average mass cannot be determined from provided information.

Tags

NGSS.MS-PS1-1

To calculate average atomic mass, you need

• the atomic mass of each isotope

• the percent abundance of each isotope

• the atomic mass and percent abundance of each isotope

• to find the average of the atomic masses of each isotope

The element Z that exits in an exoplanet has two known isotopes, Z-35 with a percent abundance of 25%, and Z-38 with a percent abundance of 75%. What is the average atomic mass of element Z?

• 37.25 amu

• 35.75 amu

• 73 amu

• 100 amu

Chlorine has two stable isotopes: Chlorine-35 with a percent abundance of 75.78% and Chlorine-37 with a percent abundance of 24.22%. Calculate the average atomic mass of chlorine.

• 34.97 amu

• 35.45 amu

• 36.00 amu

• 37.00 amu

Tags

NGSS.HS-PS1-8

Bromine consists of two isotopes: Bromine-79 with a percent abundance of 50.69% and Bromine-81 with a percent abundance of 49.31%. What is the average atomic mass of bromine?

• 79.90 amu

• 80.00 amu

• 80.10 amu

• 81.00 amu