Atomic number revision for chemistry

Info about nucleus

Where mass of the atom lies

Made of proton and neutrons

Info about electrons

Orbit the nucleus

Takes up most of space of the atom

What is the mass number

Protons and neutrons

What is the atomic number

Number of protons

What are ions

Elements with different number of electrons

What are isotopes

Elements with the same number of protons but different number of neutrons

History of the atom

1803 John dalton said that atom are spheres and that different elements are different spheres

1897 J.J Thompson discovered electrons. Plum pudding model ( positive atom with electron embedded

1909 Rutherford gold foil experiment discovered nucleus. Said its mass of the atom and its small. Fired alpha particles at thin foil

1913 Niels Bohr said that electrons exist in fixed energy shells, when electron move towards nucleus they emit IR radiation

How does electrospray ionisation work

Sample dissolved in solvent and pushed through a small nozzle at high pressure

A high voltage applied to small nozzle which cause each particle to gain H+. Then the solvent is removed

What is electron impact ipnisation

When the sample is vaporised, use electron gun to fire high energy electrons at sample, this knock of electrons from particles so leave ions

What is the definition of relative atomic mass

The mass of an atom of an element on a scale where an atom of c12 is exactly 12

Definition of relative isotopic mass

Average Mass of an atom of an isotope of a element on a scale where an atom of c12 is exactly 12

What is definition of relative molecular mass

Average mass of a molecule on a scale where an atom of C12 is exactly 12

What happens in the acceleration phase

Ions are accelerated by an electric field. Given the same KE

What happens in the ion drift

An area where no electric field

What happens at the detection phase

The detector detects the current that ions make when it hits it. Record how long ion took to travel

What is the M+1 peak

Molecular ion peak. It’s the last peak

Rules for electron configuration

Fill from the lowest energy shells

Lose electrons from highest energy shell

Fill orbits with single electrons to prevent electron repulsion

What is the exception of electrons configuration and why

Chromium and copper

Lose an electron from 4s orbital and give to the 3d orbital for a more stable shell

What is the definition of ionisation energy

The minimum energy required to lose 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of gaseous ions

What type of process is ionisation energy

Endothermic process