Mass Spectrometry Lesson

What do the peaks on the mass spectrum represent?

• anions
• different isotopes
• atoms with differing numbers of electrons
• numbers of electrons

What do the heights of the peaks represent in the mass spectrum?

• number of isotopes
• relative abundance of each isotope
• average atomic mass
• charge:mass ratio

How many isotopes are shown in this mass spectrum?

• 1
• 84
• 86
• 4

Use your periodic table.  There are two isotopes of rubidium: ⁸⁵Rb and ⁸⁷ Rb. Which is more abundant?

• equally abundant
• rubidium-85
• rubidium-85.47
• rubidium-87

Tags

NGSS.HS-PS1-1

Carbon has three known isotopes. Which is the most abundant?

• carbon-12.011
• carbon-12
• carbon-13
• carbon-14

What is the average atomic mass for this element?

• 10 amu
• 10.8 amu
• 19.9 amu
• 11 amu

How many stable isotopes are represented on the mass spectrum?

• 1

• 2

• 3

• 4

• 5

What is the average atomic mass based on the mass spectrum data?

• 24.32 amu

• 22.99 amu

• 30.84 amu

• 25.00 amu

Tags

NGSS.HS-PS1-7

To which element does this mass spectrum belong?

• Na

• Mg

• Al

• Ne

The mass spectrum of a natural abundance of chlorine atoms is shown in the figure. Detailed analysis shows that the two stable isotopes of chlorine have masses of 34.969 amu and 36.966 amu. What are the mass numbers of the two isotopes of chlorine?

• 34.969 amu and 36.966 amu

• 34 and 36

• 35 and 37

• 17 and 17