Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Aqa A Level Chemistry > Atomic Structure > Flashcards

Atomic Structure Flashcards

You may prefer our related Brainscape-certified flashcards:
Periodic Table flashcards Chemistry 101 flashcards AP® Chemistry flashcards Organic Chemistry 101 flashcards
1
Q

Atoms made up of

A

Protons, neutrons and electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Electrons describe

A

-1 charge

Whizz around nucleus in orbitals. Orbiter take up volume of atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Nucleus of atom describe

A

Most of mass of atom is concentrated in nucleus
Diameter of nucleus of rather titchy compared to whole atom
Nucleus where you find proteins and neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Proton

A

1 mass

+1 charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Neuton

A

1 mass

0 charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Electron e-

A

1/2000 mass

-1 charge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What can you figure out from nuclear symbol

A

Number of protons, neutrons and electrons in an atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the mass number?

A

Total number of protons and neutrons in nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Elements made of

A

Atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the atomic (proton) number?

A

Number of protons in nucleus it identifies the element

All atoms of same element have same number of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is sometimes left out?

A

The atomic number of the nuclear symbol because you don’t need it because the elements symbol tells you it’s value

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Neutral atoms number of protons and electrons?

A

Which have no overall charge the number of electrons is the same as the number of protons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the number of neutrons?

A

The mass number minus the atomic number

Top minus bottom in nuclear symbol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do atoms form ions?

A

By gaining or losing electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Negative ions have more

A

Electrons than protons
e.g. Br-
Negative charge means 1 more electron than there are protons
Br has 35 protons do Br- must have 36 electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Positive ions

A

Have fewer electrons than protons
E.g. Mg2+
2+ charge means 2 fewer electrons than there are protons Mg had 12 protons so Mg2+ must have 10 electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are isotopes

A

Isotopes of an element are atoms with same number of protons but different number of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What do different mass numbers mean for isotopes?

A

Different number of neutrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Atomic numbers for isotopes?

A

Are the same because both isotopes have 17 protons and 17 electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the periodic table give?

A

Atomic number of each element

Other number by elements symbol in periodic table isn’t mass number through its relative atomic mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

At the start of the 19th century, atom structure model?

A

John Dalton described atoms as solid spheres and said different spheres made up different elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

In 1897, atom structure model?

A

J.J Thomson discovered the electron. This showed stone weren’t solid and indivisible. Solid sphere idea of atomic structure had to be changed. New model known as “plum pudding model”

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

1909 atom structure model?

A

Ernest Rutherford and student Hand Geiger and Ernest Marsden conducted their famous gold foil experiment?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What did they do for the Gold foil experiment?

A

Fired positively charged alpha particles at a very thin sheet of gold.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What would the plum pudding model suggest should have happened in the gold foil experiment?

A

Most alpha particles would be slightly deflects by positive pudding that made up most if the atom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What were the results of the gold foil experiment?

A

Most particles passed straight through gold

Only small number deflected backwards

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Results of gold foil experiment meant?

A

Plum pudding model couldn’t be right so Rutherford developed nuclear model of atom.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Ruthfords model of atom?

A

Tiny positively charged nucleus surrounded by cloud of negative electrons most of atom is empty space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What did scientists realise?

A

Electrons in a cloud around the nucleus of an atom as Rutherford described would quickly spiral down into buckets causing atom to collapse

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Niels Bohr?

A

Proposed a new model of atom where electrons exist in shells or orbits of fixed energy. When electrons move between shells electromagnetic radiation with fixed energy or frequency is emitted or absorbed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What did the Bohr model do?

A

Fitted experimental observations of radiation emitted and absorbed by atoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What did scientists later discover?

A

Not all electrons in a shell have the same energy meaning the Bohr model wasn’t quite right so they refined it to include sub-shells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

The refined Bohr effect?

A

Isn’t perfect
More accurate models exist today
Useful because it’s simple and explains many experimental observations like bonding and ionisation energy trends

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

Relative atomic mass Ar is?

A

Average mass of an atom of an element on the scale where an atom of carbon-12 is 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Relative isotope mass?

A

Mass of an atom of an isotope of an element on a scale where an atom of carbon-12 is 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Relative atomic mass describe?

A

Average not usually whole number

Relative isotope mass usually whole number

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

Relative molecular mass Mr is?

A

Average mass of a molecule on a scale where an atom of carbon-12 is 12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How to find relative molecular mass?

A

Just add up relative atomic mass values of all atoms in a molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

Relative formula used instead of relative molecular mass when?

A

Ionic or giant covalent compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

To five the relative formula mass?

A

Add up relative atomic masses of all atoms in formula unit

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What can mass spectrometer?

A

Relative atomic mass, relative molecular mass, relative isotope abudance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

Vaporisation and ionisation

A

Sample dissolved and pushed through small nozzle at high pressure. High voltage applied to it causing particles to lose an electron and turning sample to positive ions gas (electrospray ionisation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Acceleration

A

Postive ions accelerated by electric field (positively charged particles needed) ions with lower mass/ charge ratio experience greater acceleration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

Ion drift

A

When ions leave electric field they have constant speed and kinetic energy so enter region with no electric field so drift. Lower mass/charge ratio drift quicker.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

Detection

A

Ions have lower mass/ charge ratio travel quicker in drift region they reach detector in less time than ions with high mass/ charge ratio. Detector detects charged particles and mass spectrum produced

46
Q

Y axis of mass spectrum graph?

A

Abudance of ions often percentage for elements height of each peak gives relative isotope abundance

47
Q

If sample is an element what will each line represent?

A

Different isotope of element

48
Q

X units

A

Mass/charge

Can assume relative isotopic mass

49
Q

How to calculate relative atomic mass?

A

Read % relative isotopic abundance from y acid snd relative isotopic mass multiply together to get total mass
Add totals
Divide by 100

50
Q

If relative abundance given as non-percentage

A

Total abundance may not add up to 100 don’t panic divide by total relative abundance

51
Q

How can mass spectrometry identify elements?

A

Different isotopes produce more than one line in mass spectrum because isotopes have different masses priding characteristic patterns like fingerprints to identify certain elements

52
Q

How can mass spectrometry be used to identify molecules?

A

You can get a mass spectrum for a molecular sample
Molecular ion is formed in mass spectrometer when one electron removed from molecule
Can be used to help identify unknown compound

53
Q

In currently accepted model of atom electrons have and do?

A

Have fixed energies

Move around the nucleus in certain regions called shells or energy levels

54
Q

What is each shell given?

A

A number (principal quantum number)

55
Q

What happens to principal quantum number and distance?

A

The further the shell is from the nucleus the higher its energy and the larger its principal quantum number

56
Q

Experiment shows that not all electrons in a shell?

A

Have the same energy

57
Q

How does the atomic model explain not all electrons in a shell having exactly the same energy?

A

Shells are divided into sub-shells that have slightly different energies. Sub-shells have different number of orbitals which can hold up to 2 electrons

58
Q

Sub-shell s

Number of orbitals and maximum electrons?

A

1 orbital

2 electrons maximum

59
Q

Sub-shell p

Number of orbitals and maximum electrons?

A

3 orbitals

6 electrons maximum

60
Q

Sub-shell d

Number of orbitals and maximum electrons?

A

5 orbitals

10 maximum electrons

61
Q

Sub-shell f

Number of orbitals and maximum electrons?

A

7 orbitals

14 electrons maximum

62
Q

Shell 1 sub-shell and total number of electrons?

A

1s

2 electrons

63
Q

Shell 2 sub-shell and total number of electrons?

A

2s 2p

8 electrons

64
Q

Shell 3 sub-shell and total number of electrons?

A

3s 3p 3d

16 electrons

65
Q

Shell 4 sub-shell and total number of electrons?

A

4s 4p 4d 4f

32 electrons

66
Q

How do the two electrons in each orbitals spin?

A

In opposite directions

67
Q

Three rules of electron configurations

A

1) Electrons fill up lower energy sub-shells first
2) electrons fill orbitals singly before they start sharing
3) for configuration of ions from s and p blocks of periodic table just add or remove electrons to it from highest energy occupied sub-shell

68
Q

Exception to rule 1

A

4s sub-shell has lower energy level than 3d sub-shell even though principal quantum number is bigger. 4s sub-shell fills up first.

69
Q

What do up and down arrows represent?

A

Electrons spinning in opposite directions

70
Q

Sub-shell notation?

A

Main way of showing electron configuration

71
Q

What else are sometimes used in electron configuration?

A

Noble gas symbols

72
Q

Why are chromium and copper nightmares?

A

They donate one of their 4s electrons to the 3D sub-shell because they’re happier with more stable full or half-full d sub-shells

73
Q

Chromium atom

A

1s2 2s2 2p6 3s2 3p6 3d5 4s1

74
Q

Copper atom

A

1s2 2s2 2p6 3s2 3p6 3s2 3p6 3d10 4s1

75
Q

Fe ion 26

A

1s2 2s2 2p6 3s2 3p6 3d6 4s2

76
Q

Fe3+ 23

A

1s2 2s2 2p6 3s2 3p6 3d5

77
Q

What determines chemical properties of an element?

A

The number of outer shell electrons

78
Q

The s block elements have?

A

1 or 2 outer shell electrons that are easily lost to form positive ions with inert gas configuration

79
Q

The elects in group 5, 6 and 7 in the p block can?

A

Gain 1,2 or 3 electrons to fork negative ions with an inert gas configuration

80
Q

Group 4 and 7 can also share?

A

Electrons when form covalent bonds

81
Q

Group 0 inert gases?

A

Completely filled s and p sub-shells and don’t need to bother gaining or losing or sharing electrons. Full sub-shells make them inert

82
Q

What do d block metals (transition metals tend to do?

A

Lose S and d electrons to form positive ions

83
Q

What has a atom or molecule being ionised?

A

When electrons have been removed

84
Q

What’s the first ionisation energy?

A

The first ionisation energy is the energy needed to remove 1 electron from each atom in 1 mile of gaseous atoms to form 1 mole of gaseous 1+ ions

85
Q

Ionisation energy equation example

A

O(g) -> O+(g) + e-

Ionisation energy= +1314

86
Q

Important points about ionisation energy

A

Must use gas state symbol because ionisation energies are measured for gaseous atoms
Must refer to 1 mole of atoms as stated in definition rather than to single atom
Lower ionisation energy easier to form ion

87
Q

Factors affecting ionisation energy?

A

Nuclear charge
Distance from nucleus
Shielding

88
Q

Nuclear charge affects ionisation energy how?

A

More protons in nucleus the more positively charged the nucleus is and the stronger the attraction for electrons

89
Q

Distance from nucleus affects ionisation energy how?

A

Attraction falls off very rapidly with distance. Electron close to nucleus will be much more strongly attracted than one further away

90
Q

Shielding affects ionisation energy how?

A

As number of electrons between outer electrons and nucleus increases outer electrons feel less attraction towards nuclear charge. Lessening pull of nucleus by inner shells of electrons is called shielding

91
Q

What does a high ionisation energy mean?

A

There’s a high attraction between the electron and the nucleus and so more energy is needed to remove the electron

92
Q

How many electrons can you remove from an atom?

A

All of the electrons leaving only the nucleus

93
Q

Define the second ionisation energy

A

The second ionisation energy is the energy needed to remove 1 electron from each ion in 1 mole of gaseous 1+ ions to form 1 mole of gaseous 2+ ions

94
Q

Second ionisation for oxygen

A

O+(g)-> O2+(g)+ e-

95
Q

What happens to ionisation energies in each shell?

A

They increase because electrons are removed from an increasingly positive ion-there’s less repulsion amongst the remaining electrons so held more strongly by the nucleus

96
Q

When do big jumps in ionisation energy happen?

A

When a new shell is broken into an electron is being removed from a shell closer to the nucleus

97
Q

What can successive ionisation energies graph tell you about an element?

A

Which group of the periodic table it belong to. Just count how many electrons are removed before the first big jump to find the group number

98
Q

What can successive ionisation energies graph be used to predict?

A

The electron structure of elements working from right to left count how many points before each big jump to find out how many electrons are in each shell starting with the first

99
Q

What happens to first ionisation energy going down a group of the periodic table?

A

Decrease

100
Q

What will the first ionisation energy of elements across a period generally do?

A

Increase

101
Q

What does the first ionisation energies of group 2 elements give evidence for?

A

That electrons shells do exist and that successive elements down the group have extra bigger shells

102
Q

What happens if elements down group 2 have extra electron shells compared to the once above?

A

The extra inner shell will shield the outer electrons from attraction of the nucleus
Outer electrons are further away from the nucleus do nucleus attraction will be greatly reduced

103
Q

What do these two factors mean for ionisation energy?

A

It will make it easier to remove outer shell electrons resulting in a lower ionisation energy

104
Q

What happens as you move across a period?

A

The general trend is for ionisation energies to increase

105
Q

Why does across a period make ionisation energies increase?

A

number of protons is increasing meaning strong nuclear attraction.
All electrons roughly equal energy level even if outer shell at different orbital types.
Therefore generally little shielding effect of extra distance to lessen attraction from nucleus

106
Q

Where is aluminium’s outer electron?

A

In 3p orbital rather than 3s.

107
Q

Two factors overriding effect of nuclear charge resulting in ionisation energy dropping slightly?

A

3p orbital slightly higher energy than 3s orbital do electron on average is further away from nucleus
3p orbital has additional shielding provided by 3s2 electrons

108
Q

What does this pattern give evidence for?

A

The theory of electron sub-shells

109
Q

What is the drop between group 5 and 6 due to?

A

Electron repulsion

110
Q

What is identical in phosphorus and sulfur atoms?

A

Shielding of identical

Electron being removed from identical orbital

111
Q

What makes first ionisation energy of sulfur lower than phosphorus?

A

In phosphus, electron being removed from singly-occupied orbitals.
Sulfur, electrons being removed from orbital containing two electrons. Repulsion between two electrons in orbitals means electrons are easier to remove from shared orbitals

112
Q

What’s this evidence for?

A

Electronic structure model

Aqa A Level Chemistry (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions