C2 Atoms And Electrons Flashcards
Proton
mass 1
Charge +1
Neutron
Mass 1
Charge 0
Electron
Mass 1/2000
Charge -1
Atomic number
The number of protons in an atom of an element
Sometimes referred to as the proton number
Mass number
The number of protons and electrons in the nucleus of an atom
Sometimes referred to as the nucleon number
Ion
An electrically charged particle formed by the loss or gain of one or more electrons from an atom or a group of atoms
Isotopes
Atoms of the same element that have different masses. The isotopes of an element have the same number of protons (and electrons), but different number of neutrons
Mass spectrometer
A gaseous sample is bombarded with high energy electrons which knock off electrons from the edge of an atom to create positive ions
They are separated and the 1+ ions are fouces in a stream to pass through a magnetic field at a constant speed
The ions are deflected and the degree of deflection depends on the mass of the ion
ONLY analyses positive ions
Mass spectra of elements
Mass spectrometer provides information about the masses of every particle formed in the machine
Looks like a stick diagram
Stick= abundance
Molecular ion peak
The peak corresponding to the relative molecular mass of the compound
Sometimes referred to as the parent ion peak
Identifying isotopes
Due to the precision isotopes can be found along with small number of ions present in isotopes within the substance
Accuracy of mass spectrometer
Originally designed by Francis Aston
Today’s models are much smaller and accurate to 4 d.p
Ground state
Show how an atom naturally exists with its electrons in their lowest energy position
1st Ionisation energy
The energy required to remove 1 electron from 1 atom in 1 mole of gaseous atoms to for, 1 mole of gaseous 1+ ions
2 Ionisation energy
The energy required to remove 1 electron from each 1+ ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions
The nth Ionisation energy
The energy required to remove 1 electron from each (n-1)+ ion in 1 mole of gaseous (n-1)+ ions to form 1 mole of gaseous n+ ions
Successive ionisation energies
Large jumps in ionisation energy after the 7th and 15th ionisation energy
Indicates 7 electrons in outer shell
Large jumps in ionisation energy indicate a new electron she’ll closer to the nucleus
Evidence for the existence of sub shells
Graph: x- atomic number
y- first ionisation energies
Steep incline between H & He
Rapid decline from He to Li
2 peaks between Li & Ne
Pattern continuesPrinciple quantum numbers
The numbers 1,2,3 etc.
Which are then divided in various sub shells s,p,d & f
Energy levels
S= sharp P= principle D= diffuse F= fundamental
Energy level order
1s
2s
2p 3s
3p 4s
3d 4p 5s
4d 5p 6s
4f 5d 6p
5f 6d
5g 6f
6g
6hOrbital
A region around the nucleus of an atom that can hold up to a maximum of 2 electrons
S orbital
Simplest type of orbital
Spherical volume of negative charge with the nucleus at the centre
P orbital
Elongated dumbbell shape
Variable charge density
Area of greatest concentration increasing with the distance from the nucleus as the principal quantum number increases
Each principal quantum number= 3 p orbitals
Identical, same energy but differing in space
X,y,z = 3 principle axis
