C1. Atomic Structure

Question 1

Who proposed the idea of elements and substances that could not be made simpler?

Answer 1

Robert Boyle 1661

Question 2

Who proposed the idea that elements were composed of indivisible atoms, atoms of particular elements had same mass ?

Answer 2

John Dalton 1803

Question 3

Who proposed the idea that electrons were located within the atom in circular arrays , plum pudding model

Answer 3

J.J Thomson 1896

Question 4

Who proposed the idea that the mass and positive charge of the atom was in a tiny central nucleus?

Answer 4

Ernest Rutherford and his team 1911

Question 5

What are the 3 fundamental particles?

Answer 5

Protons, Neutrons and electrons

Question 6

What are nucleons?

Answer 6

Name given to the Protons and neutrons as they are found in the nucleus

Question 7

Whats the relative charge and mass of Neutrons?

Answer 7

1 relative mass, 0 relative charge

Question 8

Whats the relative charge and mass of Electrons?

Answer 8

1/1840 relative mass, -1 relative charge

Question 9

Whats the relative charge and mass of Protons?

Answer 9

Relative mass is 1, relative charge is +1

Question 10

What force are the protons and neutrons held together by?

Answer 10

The strong nuclear force - Much stronger than electrostatic forces of attraction

Question 11

What is the atomic number Z?

Answer 11

Number of protons

Question 12

What is the mass number A?

Answer 12

Total number of protons and neutrons in the nucleus

Question 13

What are isotopes?

Answer 13

Atoms with the same number of protons but different number of neutrons

Question 14

How do you date organic matter using isotopes?

Answer 14

Living matter has fixed portion of Carbon-14, half life of 5730 years, once living material die the C-14 decays

Question 15

Who proposed the idea that atoms consisted of tiny positive nucleus orbited by negatively charged electrons to form an atom?

Answer 15

Niels Bohr 1913

Question 16

Who proposed the idea of electrons carrying wave like properties , leading to quantum mechanics?

Answer 16

Erwin Schröndinger 1926

Question 17

Who proposed the idea of the neutron?

Answer 17

James Chadwick 1932

Question 18

Whats the equation for Number of electrons in each shell?

Answer 18

2n² (n is number of shells)

Question 19

What is the mass spectrometer used for?

Answer 19

Finding relative atomic mass

Question 20

What is the definition of relative atomic mass?

Answer 20

(Average mass of 1 atom) / (1/12 mass of Carbon 12)

Question 21

What is the definition of relative molecular mass?

Answer 21

(Average mass of 1 molecule) / (1/12 mass of Carbon 12)

Question 22

What are the 6 stages of TOF mass spectrometer?

Answer 22

Vacuum, Ionisation, Acceleration, Ion drift, Detection, Data analysis

Question 23

What occurs in vacuum of TOF?

Answer 23

High vacuum prevents collisions between ions that have been made and molecules in air

Question 24

What occurs in Ionisation of TOF?

Answer 24

electrospray ionisation or Electron gun

Question 25

What occurs in electrospray ionisation of TOF?

Answer 25

Sample dissolved in volatile solvent; positive droplets produced by injecting solution through needle to positive terminal - high voltage; particles lose electrons; Solvent evaporates leaving single positivity charged ions, Mr increases by 1

Question 26

What occurs in electron gun stage of TOF?

Answer 26

Beam of high energy electrons knock electrons out of sample creating positively charged ions and free radicals; May cause fragmentation

Question 27

What occurs in Acceleration of TOF?

Answer 27

Positive ions are accelerated by electrical field giving each ion same amount of kinetic energy; particles with lower mass / charge ratio experience greater acceleration ,they are lighter but given same amount of energy as heavier ions

Question 28

What occurs in ion drift of TOF?

Answer 28

Beam of ions leave field with constant speed and kinetic energy; beam of particles moves into flight tube , no electrical field so particles can drift; ions with lower M/z ratios drift faster than those with larger M/z ratios

Question 29

What occurs in detection of TOF?

Answer 29

Detector detects current generated as positively charged particles hit the plate , recording how long it took to drift through chamber; this is used to generate m/z values to produce mass spectrum; particles with lower m/w ratios reach detector first

Question 30

What occurs in data analysis of TOF?

Answer 30

Detector sends signal to a computer to generate a mass spectrum

Question 31

Whats the chemical equation for electron gun ionisation of X?

Answer 31

X(g) + e- = X+(g) + 2e-

Question 32

Whats the difference between Electrospray ionisation and electron gun?

Answer 32

Electrospray ionisation results in proton gain, electron gun loses electron

Question 33

What are the energy levels in orbitals?

Answer 33

s, p ,d ,f

Question 34

What is the definition of an orbital?

Answer 34

Region with maximum probability of the electron

Question 35

What is the Pauli exclusion principle?

Answer 35

Each orbital can contain a maximum of 2 electrons, 1 spin up 1 spin down

Question 36

What are the amounts of electrons each orbital hold?

Answer 36

s 1 orbital = 2; p 3 orbitals = 6; d 5 orbitals = 10; f 7 orbitals = 14

Question 37

What is the Aufban principle?

Answer 37

Electrons fill energy levels in order of increasing energy

Question 38

What are the layout of orbitals?

Answer 38

1S​;
2S 2P​;
3S 3P 3D​;
4S 4P 4D 4F​;

Question 39

What is Hund’s rule?

Answer 39

Electrons will occupy orbitals as single unpaired electrons all with same spin, then will pair up till no vacant orbitals in that sub levels