Specific Charge

Key Stage 5

Specific charge is the ratio of the charge of a particle to its mass shown in the equation \(S.C. = \frac{Q}{m}\) where 'Q' is the charge of the particle and 'm' is the mass of the particle.

The SI Units for specific charge are the Coulomb per kilogram (Ckg^-1).

The specific charge of a particle is a useful quantity when using a mass spectrometer or cloud chamber as it determines the rate of curvature of a particle with a given its velocity through a known magnetic flux density.

\(S.C. = \frac{Q}{m}\)

Where

\(S.C. =\) The specific charge of a particle.

\(Q =\) The charge of the particle.

\(m =\) The mass of the particle.

Calculate the specific charge of a proton.

Calculate the specific charge of a proton.	Calculate the specific charge of a Magnesium-24 2+ ion.
1. State the known quantities in SI Units. \(Q_{proton} = 1\times1.60\times10^{-19}\)C \(Mass_{proton} = 1\times1.67\times10^{-27}\)kg	1. State the known quantities in SI Units. The charge on an Mg 2+ ion is 2 x elementary charge. \(Q_{Mg2+} = 2\times1.60\times10^{-19}\)C The mass of Magnesium-24 2+ ion is the mass of 24 nucleons + 10 electrons. \(M_{Mg24} = (24\times1.67\times10^{-27} + 10\times9.11\times10^{-31})\)kg
2. Substitute the numbers and evaluate. \(S.C. = \frac{Q}{m}\) \(S.C. = \frac{1\times1.60\times10^{-19}}{1\times1.67\times10^{-27}}\)	2. Substitute the numbers and evaluate. \(S.C. = \frac{Q}{m}\) \(S.C. = \frac{2\times1.60\times10^{-19}}{24\times1.67\times10^{-27} + 10\times9.11\times10^{-31}}\)
3. solve the equation. \(S.C. = \frac{Q}{m}\) \(S.C. = \frac{1.60\times10^{-19}}{1.67\times10^{-27}}\) \(S.C. = 9.58\times10^{7}Ckg^{-1}\) Correct to 3 significant figures.	3. solve the equation. \(S.C. = \frac{Q}{m}\) \(S.C. = \frac{3.20\times10^{-19}}{4.01\times10^{-26}}\) \(S.C. = 7.98\times10^{6}Ckg^{-1}\) Correct to 3 significant figures.

Calculate the charge of an ion with a specific charge of .... and a mass of .....	Calculate the charge of a nucleus with a specific charge of .... and a mass of ...... and identify the element.
1. State the known quantities in SI Units.	1. State the known quantities in SI Units.
2. Substitute the numbers and evaluate.	2. Substitute the numbers and evaluate.
3. Rearrange the equation and solve.	3. Rearrange the equation and solve.

Calculate the mass of a particle with an charge of .... and a specific charge of .....	Calculate the mass of a particle with an charge of .... and a specific charge of .....
1. State the known quantities in SI Units.	1. State the known quantities in SI Units.
2. Substitute the numbers and evaluate.	2. Substitute the numbers and evaluate.
3. Rearrange the equation and solve.	3. Rearrange the equation and solve.

Calculate the atomic mass of the nucleus of an isotope of Lead with a specific charge of ........	Calculate the atomic mass of the nucleus of an isotope of Iron with the specific charge of ........ for an Iron 3+ ion.
1. State the known quantities in SI Units.	1. State the known quantities in SI Units.
2. Substitute the numbers and evaluate.	2. Substitute the numbers and evaluate.
3. Rearrange the equation and solve.	3. Rearrange the equation and solve.

Calculate the number of neutrons in an isotope of Titanium with a specific charge of ........	Calculate the number of neutrons in an isotope of Neon with the specific charge of ....... for a Neon 2- ion.
1. State the known quantities in SI Units.	1. State the known quantities in SI Units.
2. Substitute the numbers and evaluate.	2. Substitute the numbers and evaluate.
3. Rearrange the equation and solve.	3. Rearrange the equation and solve.

Calculate the number of protons in a atomic nucleus of an isotope with a mass of ..... and a specific charge of .......	Calculate the number of protons in a atomic nucleus of an isotope with a mass of ..... and the specific charge of ....... for its 5+ ion.
1. State the known quantities in SI Units.	1. State the known quantities in SI Units.
2. Substitute the numbers and evaluate.	2. Substitute the numbers and evaluate.
3. Rearrange the equation and solve.	3. Rearrange the equation and solve.