Topic 1 Atomic Structure Flashcards
What is an atom
An atom is the smallest uncharged part of an element.
The relative mass of a proton
1
The relative mass of a neutron
1
The relative mass of an electron
1/1840 = 0.000543
What is the atomic number
The atomic number is the number of protons in an atom
What is the mass number
The total number of particles in the nucleus
(No. of protons + neutrons)
What is the no. of neutrons
Mass number - Atomic number
What are isotopes
Isotopes are the same type of atoms (same no. of protons/atomic number) but a different no. of neutrons
What is the relative atomic mass
Relative atomic mass (Ar) is the weighted mean of the atoms of a normal sample relative to 1/12 the mass of the C-12 isotope
What is the relative isotopic mass
Relative isotopic mass is the mass of an isotope of the element relative to 1/12 the mass of the C-12 isotope
What is relative molecular mass
Relative molecular mass (Mr) is the mass of a molecule relative to 1/12 the mass of the C-12 isotope
What is the relative formula mass
Relative formula mass is the sum of all the atomic masses of all the atoms in a particular formula
alternative name to hydrogen-1
protium
alternative name to hydrogen-2
deuterium
alternative name to hydrogen-3
tritium
What are the processes in a mass spectrometer
- sample is vapourised
- sample is ionised by an electron gun shooting electrons to knock off the existing electrons
- the ions are accelerated by an electric field
4.the accelerated ions pass through a magnetic field and are deflected - the ions are detected and recorded
Why must the tube in a mass spectrometer be under vacuum
so the ions won’t collide with air molecules that could affect the path the ions are taking
What m/z mean
mass/charge