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Structure 1.2 The nuclear atom

Structure 1.2.1
Understandings: 

• ​Atoms contain a positively charged, dense nucleus composed of protons and neutrons (nucleons). Negatively charged electrons occupy the space outside the nucleus.

Learning outcomes:

• Use the nuclear symbol to deduce the number of protons, neutrons and electrons in atoms and ions.

Additional notes:

• Relative masses and charges of the subatomic particles should be known; actual values are given in the data booklet. The mass of the electron can be considered negligible.
  

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This video covers the structure of the atom. 

This video covers atomic number, mass number and the nuclear notation. 

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Structure 1.2.2
Understandings: 

• ​Isotopes are atoms of the same element with different numbers of neutrons. 

Learning outcomes:

• Perform calculations involving non-integer relative atomic masses and abundance of isotopes from given data. 

Additional notes:

• Differences in the physical properties of isotopes should be understood.

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This video covers isotopes and their physical properties. 

This video covers how to calculate relative atomic mass, Ar. 

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HL content 

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Structure 1.2.3
Understandings: 

• ​Mass spectra are used to determine the relative atomic masses of elements from their isotopic composition. 

Learning outcomes:

• Interpret mass spectra in terms of identity and relative abundance of isotopes.

Additional notes:

• The operational details of the mass spectrometer will not be assessed.

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