Abundance

An isotope has three forms.  10% have a mass of 4 amu, 20% have a mass of 5 amu and 70% have a mass of 6 amu.  Based on the percentage of abundances above, the average atomic mass will be closest to...

• 3 amu

• 4 amu

• 5 amu

• 6 amu

• 7 amu

Tags

NGSS.MS-PS1-1

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

Tags

NGSS.MS-PS1-1

If the abundance of ⁸⁵Rb is 72.2% and the abundance of ⁸⁷Rb is 27.8%,

What is the average atomic mass of rubidium?

Calculate the average atomic mass of silver.

An unknown element has three isotopes. Given the abundances and relative masses, determine which element it is.

HINT: You do NOT need to calculate anything here.

• Uranium

  Mass: 238.03

• Fluorine

  Mass: 19.00

• Mercury

  Mass: 200.59

• Polonium

  Mass: 209

Tags

NGSS.HS-PS1-7

NGSS.HS-PS1-8

1.00794 is the (a)   atomic ​ (b)   for hydrogen

• minimum
• number
• average
• maximum
• mass

Tags

NGSS.MS-PS1-1

The average relative atomic mass of Vitellium (Vi) must be ​ (a)   the mass of the isotope called ​ (b)  

• closest to
• Vi–193.
• Vi–191
• Vi–188
• equal to

Using the atomic masses and relative abundance of the isotopes of nitrogen given, determine the average atomic mass of nitrogen.

N-14: 14.003 amu; 99.63% N-15: 15.000 amu; 0.37%

• 14.003 amu

• 14.007 amu

• 14.506 amu

• 15.000 amu

• 14.002 amu

The 3 isotopes of Oxygen. are shown.

The average atomic mass of oxygen is 15.9994 amu.

Which isotope is most likely to have the greatest abundance in nature?

• O–16

• O–17

• O-18

• all three isotopes may be equally abundant

An unknown element has two naturally occurring isotopes. One has a mass of 10.01 and % abundance of 19.8%. The other has a mass of 10.99 and % abundance of 80.2%. Calculate the atomic mass.