---
title: "A student analyzes a pure sample of an unknown element using a mass spectrometer. The resulting mass spectrum is shown below.  Based on the mass spectrum, what is the average atomic mass of the element?"
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url: "https://nerd-notes.com/ubq/119580/"
date_modified: "2026-08-21T06:54:00+00:00"
---

# A student analyzes a pure sample of an unknown element using a mass spectrometer. The resulting mass spectrum is shown below.

Based on the mass spectrum, what is the average atomic mass of the element?

A student analyzes a pure sample of an unknown element using a mass spectrometer. The resulting mass spectrum is shown below.

Based on the mass spectrum, what is the average atomic mass of the element?

![A clean, grayscale mass spectrum graph with a horizontal axis and a vertical axis. The horizontal axis is labeled 'Mass-to-Charge Ratio (m/z)' with tick marks from 60 to 70 in increments of 1, and numerical labels at 60, 62, 64, 66, 68, and 70. The vertical axis is labeled 'Relative Intensity' with tick marks from 0 to 8 in increments of 1, and numerical labels at 0, 2, 4, 6, and 8. There are no gridlines. The plot contains exactly two vertical solid black spike peaks. The first peak is positioned at m/z = 63 with a height of exactly 7.0 units. The second peak is positioned at m/z = 65 with a height of exactly 3.0 units. No other peaks, gridlines, labels, text, or annotations appear.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1787295240-1IYZRO.jpg)

- **A.** \(63.0\text{ amu}\)
- **B.** \(63.6\text{ amu}\)
- **C.** \(64.0\text{ amu}\)
- **D.** \(64.4\text{ amu}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/119580/*