1. What is Mass Accuracy?

Definition: Mass accuracy measures how close a measured mass is to the theoretical mass, expressed in parts per million (ppm).

Purpose: It helps scientists and students understand the precision of mass measurements in chemistry and physics experiments.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \Delta m \) — Mass accuracy (ppm)
• \( m_m \) — Measured mass (u)
• \( m_t \) — Theoretical mass (u)

Explanation: The difference between measured and theoretical mass is divided by the theoretical mass and multiplied by 1 million to get ppm.

3. Importance of Mass Accuracy

Details: High mass accuracy is crucial in fields like mass spectrometry, helping identify chemical compounds and analyze molecular structures.

4. Using the Calculator

Tips: Enter both the measured mass and theoretical mass in atomic mass units (u). All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What does ppm stand for?
A: ppm means "parts per million" - it shows how many units of difference exist per million units of measurement.

Q2: What's a good mass accuracy value?
A: In mass spectrometry, <5 ppm is generally considered good, while <1 ppm is excellent.

Q3: What is 'u' in mass measurement?
A: 'u' stands for unified atomic mass unit, approximately the mass of one proton or neutron.

Q4: Can this calculator be used for large objects?
A: Yes, but ppm is typically used for very precise measurements of small masses like molecules.

Q5: Why multiply by 1 million?
A: This converts the fractional difference to a more readable ppm scale (1 ppm = 0.0001% difference).