Atoms Flashcards
John Dalton
All matter is made up from atoms
J.J Thompson
Plum pudding model, Atoms are divisible and contain tiny little electrons
Ernest Rutherford
Atom made up from a nucleus and extra nucleus part
Niels bohr
Electrons orbit around the nucleus in orbit
Wolfgang pauli
Concept of electron spin
James Chadwick
Nucleus contains neutrons
Order of the scientists atom models
John Dalton
J.J Thompson
Ernest Rutherford
Niels Bohr
Wolfgang Pauli
James Chadwick
Limitations of the atom model
It’s only 2D
Electrons don’t orbit the nucleus
the nucleus is 50,000 times smaller than
Orbitals
are mostly empty space (they are electron shells)
Nucleon
Term for both protons and neutrons
What force holds protons and neutrons together
The strong nuclear force
What holds together protons and electrons
Electrostatic forces of attraction
is the electrostatic forces of attraction larger or the strong nuclear force
The strong nuclear force is bigger
Proton charge (coulombs)
+1.602 times 10 to the power of -19
Neutron charge in coulombs
0
Electron charge in coulombs
-1.602 times 10 to the power of -19
Proton mass in Kg
1.673 times 10 to the power of -27
Neutron mass in Kg
1.673 times 10 to the power of -27
Electron mass in Kg
0.911 times 10 to the power of -30
RAM definition
Relative atomic mass is the average mass of an atom of an element to 1/12 of of the mass of an atom of carbon 12
Molecular mass
average mass of a molecule of an atom to 1/12 of of the mass of an atom of carbon 12
What is the empirical formula
the simplest ratio of an element in a compound
what is mass spectrometry used for
drug development, environmental testing and forensics
electron impact ionisation
the sample is vaporised
then high energy electrons from an electron gun
emits an electron which knocks off an electron from the sample forming a 1+ ion
Electrospray ionisation
sample is dissolved in a volatile solution and injected through a fine needle which is attached to a high voltage power supply. particles then gain a proton
Step two of mass spectrometry
acceleration
position ions and accelerated using an electric field so they all have the same kinetic energy
Step 3 of mass spectrometry
ion drift
the + ions travel though a hole in the negative charged plates into a tube. the time it takes to travel depends on its mass
Step 4 of mass spectrometry
Detection
the + ions hit a - electrically charged plate where they are discharged by gaining electrons.
this generates a current which can be measured for the number of ions
Electospray ionising equation
X(g) + H+ —> XH+(g)
where X is the sample
electron impact ionisation equation
X(g) —> X+ (g) + e-
Electron configuration
2 8 18
Outer electrons have more or less energy
Outer electrons have more energy than those closer to the nucleus
What orbital fills up before 3D
4S
What do half arrows represent
Electron spin
When do electrons pair up
When all orbitals are full
What orbital has 2 shapes
S orbital
What orbital has 3 shapes
P orbital
What orbital has five shapes
D orbital
Copper- what shell only half fills
4S half fills then 3D fully fills
Copper- what shell only half fills
4S half fills then 3D fully fills
ionisation energy units
KJ mol-1
Factors that affect ionisation energy
Affective nuclear charge
Distance from the nucleus
Shielding (how many energy levels)
Atom
neutral particle made up from protons and neutrons in a center nucleus and electrons orbiting the nucleus
Atomic number
the number of protons in the nucleus of an atom
Charge cloud
An area in an atom or molecule where there is a high probability of finding an electron pair
Electron
Subatomic particle with a relative mass of 1/1840 located in orbitals around the nucleus
electron configuration
the number of electrons in an atom or ion and how they are arranged
energy level
region of an atom with a fixed energy that contains electrons
first ionisation energy
the energy required to remove one mole of electrons from one mole of gaseous atoms to form one mole of gaseous +1 ions
ion
charged particle
ion
charged particle
mass number
total number of protons and neutrons in the nucleus of an atom
mass spectrometry
analytic technique used to identify elements and molecules and determine atom/molecular mass
neutron
neutral subatomic particle located in the nucleus of an atom
proton
positively charged atom located in the centre of the nucleus
ratio for chlorine abundance
9:6:1
Massspec. Reason for smaller peaks on graph that are half the mr
2+ ions that are less formed due to more energy needed to form them
Are isotopes sizes the same (nucleus radius)
Yes because they have the same affective nuclear charge
What speeds up the ions in acceleration
An electric field
Why do you not use more than the minimum energy to ionise samples in TOF
so no more than one electron is knocked off
Why must the sample be ionised
Acceleration
Detection
What might be the same on a mass spec of the same sample and why
Same peak same sample
How do van der waals arise
Electron movement induces a dipole in another molecule then an adjacent molecule
How can a mixture of methanol methanethiol be separated
Fractional distillation
How to make a functional group isomer
Make it cyclo
What element in period 3 has the highest melted point
Silicon
Giant covalent covalent bonds
Why is mass spec done under a vacuum
So no other particles can collide affecting the samples speed
What are used for stating materials in antifreeze
Polymers and paints
Alkenes
How does increased carbon length chain affect alkenes solubility in water (polar)
Decreased solubility in polar things but can disolver in other hydrocarbons
How are oxides of nitrogen produced during combustion
Oxygen and nitrogen react at high temperatures
Why do infrared gasses absorb radiation
To make bonds vibrate
Carbon neutral
No net emissions of co2 into the atmosphere
