1.1 Atomic Structure

Question 1

The subatomic particles, their charge and mass

Answer 1

Proton : 1 : +1
Neutron : 1. : 0
Electron : 1/1836. : -1

Question 2

What is an isotope

Answer 2

Same number of protons. But a different number of neutrons

Question 3

What is the arrangement of subatomic particles?

Answer 3

Protons and neutrons are held in the nucleus but a strong nuclear force. Electrostatic force of attraction holds the electrons and protons together in an atom.

Question 4

What is an isotope

Answer 4

• Atoms with the same number of protons but a different number of electrons
• different isotopes react in exactly the same way

Question 5

Niels Bohr

Answer 5

Positive nucleus, electrons orbit in shells

Question 6

Erwin Schrödinger

Answer 6

Equation that electrons have the same properties of waves

Question 7

James Chadwick

Answer 7

Discovered the neutron.

Question 8

What are electrons shells

Question 9

What’s the equation used to calculate the maximum number of electrons each shell/level can hold?

Answer 9

Maximum number of electrons = 2n^2
Where n is the number of the shell

Question 10

What is an atomic orbital?

Answer 10

A region around the nucleus that can hold up to two electrons with opposite spins

Question 11

What is the electron configuration?

Answer 11

Atom consists of energy levels, each consisting of sub levels.
Sub levels consist of orbitals which can each hold two electrons in opposite spins

Question 12

How many orbitals, and therefore electrons, can each sub level hold?

Answer 12

s sub level has 1 orbital, 2 electrons
p sub level has 3 orbitals, 6 electrons
d sub level has 5 orbitals, 10 electrons
f sub level has 7 orbitals, 14 electrons

Question 13

What is an electron considered to be?

Answer 13

A cloud of negative charge, the shape of the cloud is the shape of the orbital

Question 14

What can be said about the location of an electrons

Answer 14

Scientists can never be completely sure of the exactly location of an electrons. The orbital shows us 95% probability of where it will be

Question 15

Describe the shape of the s and p sub level

Answer 15

S is a sphere
P is a dumbbell

Question 16

What is mass spectrometry used for?

Answer 16

Used to determine the relative atomic mass of separate atoms or molecules and their abundance in a sample

Question 17

What are the stages of TOF mass spectrometry?

Answer 17

1) ionisation - converting the sample into positive ions
2) acceleration - the positive ions accelerate towards and negatively charged plate
3) drift - lighter ions travel faster and hit the detector quicker than heavier ions
4) detection - when the ions hit the detector, a current is sent through them: the greater the current, the more abundant the isotope

Question 18

Which of the forces writhing the atom are the strongest

Answer 18

• nuclear force is stronger than electrostatic force of attraction
• this overcomes the repulsion between the protons

Question 19

What is ionisation

Answer 19

The process of removing electrons to form ions

Question 20

What are the two types of ionisation

Answer 20

Electron spray ionisation and electron impact ionisation

Question 21

Describe the process of electron spray ionisation

Answer 21

• a sample is dissolved in a volatile solvent (water or methanol)
• injected through a hypodermic needle to a fine mist
• tip of the needle is attached to a high voltage positive power supply
• atom gains a proton, making them positive
• solvent evaporate away

Question 22

What is the half equation for electron spray ionisation

Answer 22

X(g) + H+ ——> XH+ (g)

Question 23

Describe electron impact ionisation

Answer 23

• electron gun sends high energy electrons through gaseous sample
• atoms lose an electron forming 1+ ions

Question 24

What is the half equation from electron impact ionisation

Answer 24

x(g) + e- ——> X+(g) + 2e-

Question 25

What is the equation for kinetic energy?

Answer 25

KE = 1/2mv^2
m - mass of the particle (kg)
V - velocity (ms^-1)

Question 26

What is the equation for time of flight

Answer 26

T = d/v
d - length of the flight tube (m)
V - velocity

Question 27

What is the aufbau principle?

Answer 27

Electrons fill energy levels first, and then orbitals in order of increasing energy (fills 1s, then 2s. Then 2p)

Question 28

What is Hunds rule

Answer 28

• fill each orbital with one electrons before going back and pairing

Question 29

What is the anomaly to aufbaus principle?

Answer 29

• 4s is filled before the 3d as it has lower energy level because it is a lower energy levels

Question 30

What is the true about the stability of sub levels

Answer 30

Half-filled and fully-filled sub levels are the most stable

Question 31

What is ionisation energy

Answer 31

The amount of energy required to remove the outermost electron from an atomic nucleus in gaseous state

Question 32

What is the trend in ionisation energies

Answer 32

• the first electron needs the least energy to remove because it’s is removed from a neutral atom
• the second electron needs more energy because it removed from an +1 ion
  Theses are successive ionisation energies

Question 33

What happens to the ionisation energy when going down a energy level

Answer 33

Ionisation energy increases substantially because the electron being removed is from an energy level closer to the nucleus therefore there is a stronger electrostatic force of attraction which requires more energy

Question 34

What is the trend in ionisation energy’s across a period

Answer 34

• generally there is an increase
• because nuclear charge (number of protons in the nucleus) increases

Question 35

What is the trend in ionisation energy down a group

Answer 35

• general decrease
• because atomic radius and shielding increases

Question 36

Describe the trend in first ionisation energy in period 3

Answer 36

• general increase
• decreases from Mg to Al because gone from s to p block which is further away therefore weaker EFOA and easier to remove
• decreases from P to S becauseouter electron in S is removed from an electron pair, repulsion, easier to remove