Unit 1 - Section 1 Flashcards Preview

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Flashcards in Unit 1 - Section 1 Deck (13)
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1
Q

What was Daltons and Thompson’s model of the atom?

A

The plumb pudding model

2
Q

What was Rutherford model of the atom?

A

A positive centre surrounded by a negative cloud

3
Q

What did Bohrs discover about the atom?

A

That electrons had fixed energy shells and going up the shell requires energy and going down them releases energy

4
Q

How to calculate relative atomic masses

A

Take the weight of the isotope and times it by the abundance, do this for all the isotopes and then add them together. Decide this by 100

5
Q

How does a mass spectrometer works?

A
  1. Electrospray ionisation - the isotopes are all given the same positive charge by knocking off electrons
  2. Acceleration - the ions are accelerated by using negatively charged plates. Gives the same kenetic energy to all the ions but because they are different weights they travel at different speeds.
  3. Ion drift - the ions travel at a constant speed, the lighter ones traveling at a faster speed
  4. Detection - the ions are detected and records how long they drifted for to find a mass/charge value
6
Q

How are electron shells organised?

A

The shells go

1s2, 2s2, 2p6, 3s3, 3p6, 4s2, 3d10

7
Q

What are the exceptions in electron configuration

A

Cr rather then being 4s2, 3d4
Cr is actually 4s1, 3d5 as this is more stable

Cu rather then being 4s2, 3d9
Cr is actually 4s1, 3d10

8
Q

What is the ionisation trend down group 2?

A

It goes down sharply till Ca which it only goes down at a lower rate

9
Q

What are the four stages of time of flight mass spectrometer?

A
  1. Ionisation
  2. Acceleration
  3. Ion drift
  4. Detection
10
Q

How are atoms ionised in mass spectrometry?

A

Atoms are ionised by knocking of an electron using an electron gun

11
Q

How are ions accelerated in mass spectrometer?

A

Using increasingly negative plates give all the ions the same kenetic energy

12
Q

Why is ion drift important in mass spectrometry?

A

Because all the ions have the same kenetic energy the heavier ions move slower because they are heavier

13
Q

How are ions detected in mass spectrometry?

A

A mettle plate with a current passing through it is hit by the ions and they absorb electrons from the plate. This corses the current to flow and this can be detected