2.2.2 Describe how the mass spectrometer may be used to determine relative atomic mass using the Carbon-12 scale.

The mass spectrometer can be used to measure the mass of individual atoms.

The mass needs to be recorded relative to some agreed standard.

As carbon is a common element (most abundant), and it is easy to transport, store, etc therefore it was chosen as the standard in 1961.

Standard Isotope	Symbol	Relative Atomic Mass
Carbon-12	12      C	12.000
Element	Symbol	Relative Atomic Mass
Carbon	C	12.011
Chlorine	Cl	35.453
Hydrogen	H	1.008
Iron	Fe	55.845