1d2 Swilley Average Atomic Mass Quick Check

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

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

Calculate the average atomic mass of the element iron (Fe) using the following data:

[Isotope / % abundance]

[Iron 54 / 6% ] [Iron 56 / 92% ] [ Iron 57 / 2% ]

• 53.7 amu

• 54.9 amu

• 5592.0 amu

• 55.9 amu

An isotope has three forms.  30% have a mass of 4 amu, 20% have a mass of 5 amu and 50% have a mass of 3 amu.  Calculate the average atomic mass and round to the nearest whole number.

• 2 amu
• 3 amu
• 4 amu
• 5 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

Tags

NGSS.MS-PS1-1