# Atomic Structure

• Created by: Ami_Bull
• Created on: 26-11-15 10:08
What is the mass of an electron?
1/1840
1 of 28
Define relative atomic mass...
The average mass of an atom of an elemtn relative to 1/12 of the mass of a carbon-12 atom.
2 of 28
Define relative isotopic mass...
The mass of a single isotope of an element realtive to 1/12 of the mass of a carbom-12 atom
3 of 28
What is the formula for calculating relative atomic mass?
(Mass x Relative abundance) + (Mass x relative abundance) / Total abundance
4 of 28
What are the 5 main stages of TOF mass spectrometry?
Electrospray ionisation, acceleration, ion drift, ion detection, data analysis
5 of 28
How is the sample ionised (TOF) to form gaseous ions?
In electrospray ionisation a hig voltage is applie to the sample by a metal coil to produce charged droplets. A solvent then evaporates the droplets to produce gaseous ions.
6 of 28
Why and how the ions are accelerated in TOF spectrometry?
An electric field is applied to the ions to give them all the same kinetoc energy, this is done using an electromagnet.
7 of 28
When and how are ions seperated in TOF spectrometry?
The ions enter a region with no electric field called the flight tube. Here the ions are sepereated based on their velocities, as they've obtrained the same kinetic energy. Smaller ions will move faster and heavier ions will move slower (F=ma)
8 of 28
How are ions detected in TOF spectrometry?
The positive ion meets the detector and a small charge is produced due to the positively charged ion and negatively charged detector meeting.
9 of 28
What two things are measured in mass spectrometry?
Relative abundance and mass/charge ratio
10 of 28
In mass spectrometry of a compound, what does tha largest peak show?
It shows the base peak which is caused by the most stable ion being formed
11 of 28
How can you determine the relative molecular mass of a compound?
Look at the last major peak
12 of 28
What is the principal quantum number?
The first energy level is n=1 and the second energy level is n=2 and so on...
13 of 28
What happens to the energy levels as they get further away from the nucleus?
They get closer together
14 of 28
What is the filling up order of the sub-shells?
1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 4f 5d 5f 5g
15 of 28
Why do chromium and copper only have one electron filling the 4s orbital?
Having 5 half filled orbital (chromium) or having 10 completly filled orbitals (copper) is more stable than having empty orbitals
16 of 28
What block of elements lose electrons from their 4s orbitals first?
d block
17 of 28
Define the term Isoelectronic
Particles that have the same electronic configuration
18 of 28
Define ionisation energies
The energy required to remove 1 mole of electrons from 1 mole of gaseous atoms to form 1 mole of gaseous ions
19 of 28
What will the first ionisation of sodium look like?
Na(g) --> Na+ (g) + e-
20 of 28
What two gases are used in a plasma tv?
Xeon and neon
21 of 28
How is an image produced in a plasma tv?
When volatge is applied the gases become ionised and collide with the elctrons in the plasma. This causes the ions to release ultraviolet photons that interacts with the phosphur inside the thv, producing visible light.
22 of 28
What are ionisation energies measured in?
kJmol-1
23 of 28
Why are all ionisation energy values postive?
They're endothermic
24 of 28
What causes the general increase in ionisation energies?
It's caused by the increase in the ratio of protons to electrons as electrons are removed, this is called effective nuclear charge
25 of 28
How does atomic radius change down a group and across a period?
Increases down the group, decreases across the period
26 of 28
How does the atomic radius effect ionisation energies and why?
The larger the atomic radius the lower the ionisation energy as they electron in the outer shell is further from the electrostatic attractions of the nucleus
27 of 28
How does the proton number effect ionisation energies?
The higher the proton number the larger the ionisation energy, this is due to a higher nuclear charge
28 of 28

## Other cards in this set

### Card 2

#### Front

Define relative atomic mass...

#### Back

The average mass of an atom of an elemtn relative to 1/12 of the mass of a carbon-12 atom.

### Card 3

#### Front

Define relative isotopic mass...

### Card 4

#### Front

What is the formula for calculating relative atomic mass?

### Card 5

#### Front

What are the 5 main stages of TOF mass spectrometry?