Pick an element from the dropdown to load its known isotopes (Chlorine, Neon, Carbon, Magnesium).
Press Play / Pause to control the stream of ions moving through the spectrometer schematic.
Watch ions travel through the sample inlet, ionization region, acceleration plates, magnetic deflection zone, and finally to the detector. Lighter isotopes curve more sharply.
Click any bar in the spectrum to highlight that isotope and display its exact mass and natural abundance.
Connect the animation to the bar chart: note how the detector position aligns with each bar’s relative peak height.
Included Isotope Data
Element
Isotope
Mass (amu)
Natural Abundance (%)
Chlorine
35Cl
34.96885
75.77
Chlorine
37Cl
36.96590
24.23
Neon
20Ne
19.99244
90.48
Neon
21Ne
20.99385
0.27
Neon
22Ne
21.99138
9.25
Carbon
12C
12.00000
98.93
Carbon
13C
13.00335
1.07
Magnesium
24Mg
23.98504
78.99
Magnesium
25Mg
24.98584
10.00
Magnesium
26Mg
25.98259
11.01
Lesson Integration Ideas
Claim-Evidence-Reasoning: Ask students to justify the average atomic mass printed on the periodic table using the simulated spectrum as evidence.
Prediction Challenge: Pause the ion beam, cover the chart, and have students sketch the expected deflection order for each isotope before revealing the bars.
Extension: Have students adjust textbook practice problems to use the isotope abundances shown here, then compare calculated weighted averages versus the simulation output.
Learning Objective Alignment
Bloom’s Analyze: Interpret the distribution of peak heights to determine isotopic composition.
Bloom’s Evaluate: Predict how changing the natural abundance of an isotope would alter both the detector hit pattern and the average atomic mass.