Atoms and molecules
23/09/19
- Basic atomic theory (+ve protons, -ve elections and neutral neutrons)
- Proton number (defines element), neutron number (can change with isotopes), electrons
(=proton number in a neutral atom)
- Neutrons and protons are similar and are measured in Daltons (kilodaltons for larger mols.
E.g. proteins)
- Mostly GCSE and AS level stuff so just a recap
• Isotopes = atom with same proton number but different neutron number therefore differing
masses to other isotopes of same element
• Isotopes are uses as medical tracers e.g. PET (Position Emission Tomography)
• A lot of isotopes become radioactive so are used as radiotracers. Radiotracers are molecules
‘labelled with some radioactive material (from said isotope). This is detectable on a PET
scanner
• They accumulate around regions inflammation/tumours and bind to specific proteins.
• A commonly used radiotracer is F-18 fluorodeoxyglucose (FDG) which is a molecule similar to
glucose. The radiotracer may be swallowed, inhaled or injected
• Because cancerous cells are more metabolically active than regular cells, they may absorb
glucose at a faster rate, therefore, FDG is effective due to its similar structure to glucose.
• This is result is seen on PET scanners and interoperate by doctors who can diagnose a patient.
• This is a basic example of how isotopes are effective in medicine.
- Atomic number = no. protons
- Mass number = mass relative to C-12
- 1st shell in an atom of an element has the lowest energy where as the 3rd shell etc. has the
highest energy.
- Outermost (valance) electrons are involved in reactions
- Mostly GCSE and AS level stuff so just a recap but the energy levels (s, p, d, f) weren’t covered
in the lecture so make sure you know it.
Bonding
Ionic:
- Electrostatic forces of attraction between opposite charges. Between metals and Non metals
- E.g. – NaCl (Na+ and Cl-) forms Ionic lattice and is water soluble
23/09/19
- Basic atomic theory (+ve protons, -ve elections and neutral neutrons)
- Proton number (defines element), neutron number (can change with isotopes), electrons
(=proton number in a neutral atom)
- Neutrons and protons are similar and are measured in Daltons (kilodaltons for larger mols.
E.g. proteins)
- Mostly GCSE and AS level stuff so just a recap
• Isotopes = atom with same proton number but different neutron number therefore differing
masses to other isotopes of same element
• Isotopes are uses as medical tracers e.g. PET (Position Emission Tomography)
• A lot of isotopes become radioactive so are used as radiotracers. Radiotracers are molecules
‘labelled with some radioactive material (from said isotope). This is detectable on a PET
scanner
• They accumulate around regions inflammation/tumours and bind to specific proteins.
• A commonly used radiotracer is F-18 fluorodeoxyglucose (FDG) which is a molecule similar to
glucose. The radiotracer may be swallowed, inhaled or injected
• Because cancerous cells are more metabolically active than regular cells, they may absorb
glucose at a faster rate, therefore, FDG is effective due to its similar structure to glucose.
• This is result is seen on PET scanners and interoperate by doctors who can diagnose a patient.
• This is a basic example of how isotopes are effective in medicine.
- Atomic number = no. protons
- Mass number = mass relative to C-12
- 1st shell in an atom of an element has the lowest energy where as the 3rd shell etc. has the
highest energy.
- Outermost (valance) electrons are involved in reactions
- Mostly GCSE and AS level stuff so just a recap but the energy levels (s, p, d, f) weren’t covered
in the lecture so make sure you know it.
Bonding
Ionic:
- Electrostatic forces of attraction between opposite charges. Between metals and Non metals
- E.g. – NaCl (Na+ and Cl-) forms Ionic lattice and is water soluble
