Atomic Calculations and Mass Spectrometry. Quantum Orbital Video. Atomic Mass – Atomic Number = # Neutrons (p + n) - (p) = (n). 110. Complete the following chart: protonselectronsneutrons H Zr Ca 2+ P 3- Al 3+ Cl -. 404051. 201820.
Atomic Calculations and Mass Spectrometry
Quantum Orbital Video
Atomic Mass – Atomic Number = # Neutrons
(p + n) - (p) = (n)
Complete the following chart:
Isotopes- same atomic number but different mass
For example, there are 3 types of hydrogen atoms.
1H 2H 3H
Not all atoms of the same element are identical.
Are used to determine the abundance and mass of the isotopes of elements
A device known as a mass spectrometercan be used to determine the relative abundanceand the mass of the isotopes of elements.
In the graph the isotopes of a sample of the element zirconium can be seen in their relative abundances.
The data can be summarized as follows:
90Zr90.00 amu 51.5 %
91Zr91.00 amu 11.2 %
92Zr92.00 amu 17.1 %
94Zr94.00 amu 17.4 %
96Zr96.00 amu 2.80 %
atomic mass of isotope 100 %
Calculate the weighted average mass of zirconium using the data above.
Change each percent to a decimal by dividing by 100.
Multiply by the mass.
Add it all together.
3 sig figs!
Look up the mass on the periodic chart.
The unit amu describes how many times heavier than the mass of H
They are the same with uncertainty
Calculate the average atomic mass for Germanium
(0.2052)(69.92428) + (0.2743)(71.92174) + (0.0776)(72.9234) + (0.3654)(73.92115) + (0.0776)(75.9214) =
Periodic Table=72.6 amu