Atomic structure Flashcards
what is the trend in successive ionisation energy ?
It increases
How are the ions detected at the detector ?
They reach the detector and gain an electron which creates a current which is directly proportional to its abundance.
What is the atomic number ?
Number of protons
What is the formula for KE
KE=1/2 m v^2
Why is the flight tube a vacum ?
To prevent the sample colliding with the air molecules.
What is the trend of IE down the group ?
Decreases
What causes Ion drift ?
All particles are given the same KE but have varying masses therefore have different velocities.
Explain electron impact ionisation.
High energy electrons are fired from an electron gun at a gaseous sample, the electrons collide with the particles and knock off electrons to form positive ions.
What are the factors that affect IE ?
Nuclear charge
DIstance from nucleus
shielding
What is a isotope ?
A atom with the same number of protons and electrons but different number of neutrons
What is a ion ?
A atom which has lost or gained one or more electrons.
What is the trend in atomic radius down the group ?
increases
Why is Li bigger than Be
Same shielding but Be has higher nuclear charge so stronger attraction between nucleus and electrons.
where are protons and neutrons found ?
in the nucleus
What is the current created at the detector directly proportional to ?
relative abundance
Why is Li bigger than He
He has less shielding so stronger attraction between nucleus and electronstherefore it is smaller.
Why is the sample fired at a negative plate ?
So that it can be given KE and accelerated towards the detector.
What is avogadro’s constant
6.022x10^23
Why do isotopes have the same chemical properties ?
They have the same electronic configuration
What is the electronic configuration for the first 2 exceptions in IE ?
xP1
xP4
Why is Cu 3d10 instead of 3d9 ?
it loses a electron from the 4s subshell and gains it in the 3d subshell because it is more stable
How do you find the number of neutrons ?
Mass number - atomic number
Explain the results of the gold foil experiment.
Most passed through because atom is mostly empty space, few were deflected and reflected because the mass is concentrated in a positive nucleus
What is a positive ion ?
cation
Why is B first IE lower than BE ?
B outer electron is in the p subshell which means it is higher in energy so less energy is required to remove it
What is the mass number ?
Number of protons and neutrons
What is m/z
Mass charge ratio
Explain electrospray ionisation.
Sample is dissolved in a volatile solvent and is sprayed through a hypodermic needle ,needle has high voltage so as the sample leaved the needle it gains a proton and forms + ion so it can be accelerated/detected and gives a aerosol.
What is the trend in first IE across the period ?
Increases because nuclear charge increases so stronger attraction between outer electrons and nucleus.
what is first ionisation energy ?
amount of energy required to remove a mole of electrons from a mole of atoms in a gaseous state
Why is O first IE lower than N ?
O outer most electron is paired so less energy is required to remove it because like charges repel.
What are the electronic subshells ?
S
D
P
F
What is the electronic configuration of oxygen ?
1s2 2s2 2p4
How do you calculate Ar ?
(M1xA1)+(M2xA2)……/total abundance
Why is Cr 3d5 instead of 3d4 ?
it loses a electron from the 4s subshell and gains it in the 3d subshell because it is more stable
What are the charges and masses of the 3 subatomic particles ?
+1 1
0 1
-1 1/1840
Why does IE increase after going down a shell ?
decrease in shieldingtherefore stronger attraction btween electrons and posotive nucleus
What are the 3 subatomic particles ?
Proton
Neutron
Electron
what is a negative ion ?
anion
