Chapter 1- Atomic Structure

Question 1

How do you calculate relative atomic mass?

Answer 1

(Abundance 1 x Mass 1)…./
Sum of abundances

Question 2

State the relative mass of the subatomic particles.

Answer 2

Proton, neutron= 1; electron=0

Question 3

How do you calculate the number of electrons in each shell?

Answer 3

2n^2

Question 4

State the relative charge of the subatomic particles.

Answer 4

Electron=-1; Proton=1; Neutron=0

Question 5

What is the aufbau principle?

Answer 5

Electrons will fill the lowest energy level first, then the second lowest and so on.

Question 6

What is a sub-shell?

Answer 6

A more precise description of where an electron is most likely to occupy

Question 7

What are the ‘names’ of the sub-shells?

Answer 7

s,p,d,f

Question 8

What are sub-shells divided into?

Answer 8

Orbitals

Question 9

How many electrons can occupy each orbital?

Answer 9

2

Question 10

How many orbitals can the s sub-shell accommodate?

Answer 10

1

Question 11

How many orbitals can the p sub-shell accommodate?

Answer 11

3`

Question 12

How many orbitals can the d sub-shell accommodate?

Answer 12

5

Question 13

What is an electron?

Answer 13

A probability cloud of negative charge

Question 14

What is pauli’s exclusion principle?

Answer 14

Orbitals can hold up to 2 electrons as long as they have opposite spin.

Question 15

Why are sub-shells not always filled numerically, and provide an example

Answer 15

as electrons occupy the lowest energy subshell available, eg 4s fills before 3d.

Question 16

How can you draw electronic configuration?

Answer 16

orbitals as boxes, electrons as half arrows depending on their spin.

Question 17

State the electron configuration of Oxygen

Answer 17

1s2,2s2,2p4

Question 18

Explain why chromium and copper are exceptions?

Answer 18

4s and 3d subshells are close in energy and it is more stable to have a full 3d subshell than a full 4s orbital.

Question 19

Which electron do atoms lose first when forming ions?

Answer 19

Their highest energy electron

Question 20

During ionisation, which electrons do transition metals lose first

Answer 20

Their 4s electrons.

Question 21

Write the shorthand electron configuration for sodium

Answer 21

[Ne] 3s1

Question 22

How can you use the periodic table to quickly work out electron configuration?

Answer 22

If group 1/2- s orbital
If transition metal- d orbital
If group 3/8- p orbital

Question 23

What is a mass spectrometer

Answer 23

A scientific instrument used to accurately determine Relative Atomic mass.

Question 24

What are mass spectrometers used for

Answer 24

Separating atoms or molecules by their charge and mass to identify substances and calculate isotopic abundance.

Question 25

What are the 4 stages to regular mass spectrmetry

Answer 25

Ionisation
Acceleration
Deflection
Detection

Question 26

What conditions are needed for mass spectrometry

Answer 26

Vacuum, gaseous state

Question 27

How are molecules ionised in electron beam ionisation

Answer 27

Electrons knock electrons from atoms, creating 1+ ions

Question 28

How are electrons accelerated in spectrometers

Answer 28

-ve charged plates

Question 29

State 2 differences in Time of flight mass spectrometry

Answer 29

Ionisation- uses electrospray ionisation (ionisation by gaining a proton)
Ion drift- particles given same kinetic energy and mass calculated by time taken to reach the detector.

Question 30

What ratio do spectrometers calculate

Answer 30

mass/charge
m/z

Question 31

What do mass spectra show?

Answer 31

The relative abundance of each ion.

Question 32

What is unique to the mass spectra of diatomic molecules

Answer 32

spectra will show other peaks where diatomic molecules have been ionised together.

Question 33

Define Relative atomic mass

Answer 33

The average mass of an atom of an element compared to 1/12th of an atom of Carbon-12

Question 34

Define ionisation energy

Answer 34

The energy required to remove 1 electron from each atom in 1 mole of gaseous atoms to form 1 mole of gaseous 1+ ions

Question 35

Why does IE increase as more electrons are removed?

Answer 35

As the ion becomes more positively charged, so more energy is needed to remove the electron

Question 36

Write an equation to show the first ionisation of Sodium

Answer 36

Na (g)-> Na+ (g) +e-. Must include gaseous state

Question 37

State 4 factors affecting IE

Answer 37

-Atomic Radius- distance from nucleus
-Nuclear force- +ve charge of nucleus
-Electron shielding- -ve electrons shield outer electrons from nucleus.
-Electron pairing- paired electrons repel each other

Question 38

Describe the change in IE across a period

Answer 38

General increase. slight decrease when moving up a sub-shell. slight decrease when electrons begin pairing up in p and d orbitals.