Particles + Mass spec

Question 1

What do atoms consist of? - 2 points

Answer 1

-Nucleus
-Energy levels/shells

Question 2

What are the subatomic particles? - 3 points

Answer 2

• protons
• electrons
• neutrons

Question 3

What is a proton’s relative mass?

Answer 3

1

Question 4

What is a proton’s relative charge?

Answer 4

+1

Question 5

What is a neutron’s relative mass?

Answer 5

1

Question 6

What is a neutron’s relative charge?

Answer 6

0

Question 7

What is an electron’s relative mass?

Answer 7

1/1840 or 1/1836

Question 8

What is an electron’s relative charge?

Answer 8

-1

Question 9

Atomic mass

Answer 9

Protons

Question 10

Mass number

Answer 10

Protons and neutrons

Question 11

What is the name given to protons and neutrons in the nucleus?

Answer 11

Nucleons

Question 12

What is the nucleus diameter?

Answer 12

10^-15m

Question 13

What is the atom diameter?

Answer 13

10^-10m

Question 14

How are nucleons held together in the centre?

Answer 14

Strong nuclear force

Question 15

Which is stronger - electrostatic forces of attraction or strong nuclear force

Answer 15

Strong nuclear force

Question 16

How is repulsion in the nucleus overcome?

Answer 16

The strong nuclear forces are stronger than the electrostatic forces of attraction (which hold the protons and electrons in place)

Question 17

What are isotopes?

Answer 17

Atoms with:
- same no. of protons
- diff no. of neutrons
- similar chemical properties, different masses

Question 18

What is a mass spectro meter?

Answer 18

it is used to DETERMINE ALL THE ISOTOPES PRESENT IN a SAMPLE of an ELEMENT -> IDENTIFY ELEMENTS

Question 19

What must a mass spectrometer be under?

Answer 19

A vacuum

Question 20

Why must a mass spectrometer be under a vacuum?

Answer 20

Or else air particles would ionise and register

Question 21

What are the parts of a mass spectrometer? - 4 points

Answer 21

• ionisation area
• acceleration area
• ion drift area/ deflection / flight tube
• detection area

Question 22

What are the types of ionization? - 2 points

Answer 22

• electron impact
• electro spray ionisation

Question 23

What is electron impact used for?

Answer 23

Substances with low formula masses

Question 24

Why can’t larger organic molecules undergo electron impact ?

Answer 24

The would break under such heavy impact

Question 25

What is electro spray ionisation for?

Answer 25

Larger organic molecules, this technique is softer so it won't cause the molecule to break

Question 26

What happens during electron impact? - 4 points

Answer 26

- sample is VAPORISED and INJECTED at LOW PRESSURE - ELECTRON GUN FIRES HIGH ENERGY ELECTRONS at SAMPLE - an OUTER ELECTRON is KNOCKED OUT - POSITIVE IONS are FORMED e.g. Ti -> Ti+ + e-

Question 27

What is a particle’s velocity dependant on?

Answer 27

Particle’s mass

Question 28

What velocity do lighter particles have?

Answer 28

Faster velocity

Question 29

What velocity does heavier particles have?

Answer 29

Slower velocity

Question 30

What happens during acceleration?

Answer 30

POSITIVE IONS are ACCELERATED BY AN ELECTRIC FIELD to a CONSTANT KINETIC ENERGY

Question 31

What area do the heavier particles and the lighter particles get distinguished?

Answer 31

Ion drift area/ flight tube

Question 32

What happens to particles in the ion drift area/ flight tube? - 2 points

Answer 32

- lighter particles move faster - heavier particles move slower

Question 33

How are ions distinguished in the ion drift area/ flight tube?

Answer 33

Flight times

Question 34

Where are ions detected in the mass spectrometer?

Answer 34

The detection area

Question 35

How can the computer analyse ions?

Answer 35

When the IONS ENTER the detector, a SMALL CURRENT is GENERATED

Question 36

How is a current produced in the detection area?

Answer 36

ELECTRONS IN the DETECTOR TRANSFER TO the POSTIVE IONS

Question 37

Relative atomic mass calculation using detection graph

Answer 37

(Abundance x m/z) + (abundance x m/z) / 100

Question 38

Relative atomic mass using detection graphs (relative abundance)

Answer 38

(Relative abundance x m/z) + (relative abundance x m/z) / sum of relative abundance

Question 39

What element can be used to represent a proton?

Answer 39

Hydrogen - H+