Average Atomic Mass Practice Quiz

The atomic mass of an element is the ___.

• average of the mass number and the atomic number for the element

• weighted average of the masses of the isotopes of the element

• total mass of the isotopes of the element

• total number of subatomic particles in the nucleus

If an atom contains exactly eight protons, then it's an atom of _____

• lithium

• gold

• nitrogen

• oxygen

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 mass and percent abundance of each isotope

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

Element Z has 2 natural isotopes. One isotope has a mass of 15.0 amu and a relative abundance of 30%. The other isotope has a mass of 16.0 amu and a relative abundance of 70%. Estimate the average atomic mass for this one element.

• 15.0 amu

• 16.0 amu

• 15.7 amu

• 16.9 amu

Chromium has four naturally occurring isotopes (chromium-50, chromium-52, chromium-53, and chromium-54). Which isotope would you predict is the most abundant? (Hint: You will need to look at the average atomic mass of chromium on the periodic table to make your decision.)

• chromium-50

• chromium-52

• chromium-53

• chromium-54