Chemistry Unit 1 Atomic Structure

Unit 1

Atomic Structure

• Atoms with the same number of protons but different numbers of neutrons are called isotopes.
• Different isotopes of the same element reacts chemically in exactly the same way.
• They vary in mass because of the different number of neutrons in their nuclei.

Mass Spectrometry

• Ionisation- a beam of high energy electrons knocks out electrons from atoms of the sample to form positive ions.
• Acceleration- these positive ions are attracted towards negatively charged plates and are accelerated at high speed. The speed they reach depends on their mass.
• Deflection- the beam of ions moves into a manetic field at right angles. This deflects the ions. The deflection depends on the m/z ratio of the ion. The deflection depends on magnetic feild strength- the stronger the field, the greater the deflection.
• Detection- the magnetic field is gradually increases so ions of increasing mass enter the detector, one after the other…