Zusammenfassung der Ressource
Atomic structure
- atomic particles
- protons (P)
- neutrons(N)
- electrons (E)
- relative mass of (n,e,p
- P; Z=+1 M=1
N; Z=0 M=1 E;
Z=-1
M=5x10(-4)
- Atomic number
- number of protons in the nucleus,
also equal number of electrons
- mass number
- number of protons and neutrons in a nucleus
- isotopes of atoms
- atoms of the same element with the same
number of protons but different number of
neutrons, they still have the same chemical
properties because the number of electrons
on the outer shiel is still the same. its just
mass that varies
- relative charge
- change of particles relative to
the electron ( like that of the electron)
- relative mass
- mass of a particle 1/12 mass of 1 atom of c12
- mass spectrometer
- to separate ions with
different masses, and
helps identify complex
molecules
- steps in mass spectrometry
- 1.vaporisation
- sample must be in a gaseous state
- 2.ionisation
- electron gun fires high energy electron at gaseous
molecule eg m(g)+e- --> m*(g) = 2e-
- 3.acceleration
- ions are accelerated by an
electrical field which then
focus into beams to pass
through slits
- 4.deflecrion
- beam of ions are deflected by a strong magnetic field,
magnitude depends on m/z ratio the smaller the m/z the
larger the deflection
- 5.detection
- the ions are directed to the detector by a
different magnetic field the ions hit the
detector and create a small electric current
the bigger the current the ore of the ion
there is the current is amplifies and sent o
computer to analyse = create spectrum
- the number of peaks created on the
spectrum = the amount of isotopes m/z of
peaks= mass of ion and hight= amount of
each isotope
- atomic mass from mass spectrum data equation
- Ar= (sum) relative mass of isotope x
abundance of isotope
- molecular mass Mr
from spectrum=
peak with highest
value = Mr
- definition of atomic mass = Ar =
mean mass of 2 atom / 1/12 of the
mass of c-12
- definition of relative
molecula mass of an
entity
- Mr= mean mass of entity/ 1/12
mass of 1 atom of c-12
- enitity =molecule e.g CH4 or NaCl
- Mr from formula
- sum of relative
atomic masses of
all atoms in
formula
- electron configuration
- electron arrangement in atom
- found in shells, lower energy are closer to nucleus
- Kr
- 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6
- for element up to Kr
element fill in the
order of Kr except
Cr;4s1 3d5 and Cu;4s1
3d10
- cations +
- ins removed in reverse order except 4s
and 3d
- atomic orbitals
- maximum of
2 electrons in
opposite spin
and are
represented
as up an
down arrows
- definaition of first ionisation energy
- energy required to remove 1 mole of
electron from 1 mol of gaseous atom
- first I.E equation... M(g) __>M=(g)=e-
- 1st I.E DOWN a group= decreases
because the outer electron have more
shielding from the attraction from the
nucleus because its further away
- ACROSS a period=
general increase
because number of
protons create
increasing nuclear
attraction while the
outer electrons in
same energy levels =
similar shielding from
nucleus
- second I.E equation..M(g)__>m2=(g)+e-
- gp 2 and gp 3
- gp 3 outer electrons are easier to remove than gp 2 because
gp 2 outer electrons is 2s or 3s and gp 3 are higher level 2p
or 3p = more shielding
- gp 5 and gp 6
- gp 6 outer electrons easier to remove than gp 5
outer electron in same sub level 2p or 3p but gp6
outer electron p4 is paired and mutual repulsion
occurs