Brainscape's Knowledge GenomeTM

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


See full index

chemisry > atomic structure > Flashcards

atomic structure Flashcards

1
Q

What is the relative mass, relative charge and position of a proton?

A

Relative mass = 1
Relative charge = +1
Position in the atom = nucleus

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

What is the relative mass, relative charge and position of a neutron?

A

Relative mass = 1
Relative charge = 0
Position in the atom = nucleus

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

What is the relative mass, relative charge and position of an electron?

A

Relative mass = 1/1840
Relative charge = -1
Position in the atom = energy levels surrounding the nucleus

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

Who discovered the electron?

A

JJ Thomson (1897)

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

Who discovered the proton?

A

Ernest Rutherford (1917)

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

Who discovered the neutron?

A

James Chadwick (1932)

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

What is the mass number of an atom?

A

The top number of the two (eg 12 in carbon)
Mass number is the number of protons + the number of neutrons in the nucleus of that atom

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

What is the atomic number of an atom?

A

The bottom number of the two (eg 6 in carbon)
Atomic number is the number of protons in the nucleus of an atom of that element, and hence is the number of electrons

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

What is an isotope?

A

Atoms of the same element with different masses

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

What is relative atomic mass of an element?

A

The weighted mean mass of an atom of the element compared to the mass of an atom of carbon-12

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

What is relative isotopic mass?

A

The mass of an atom of an isotope of the element compared to the mass of an atom of carbon-12

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

What does a mass spectrometer do?

A

Measures the masses of atoms and molecules by producing positive ions that are deflected by a magnetic field according to their mass to charge ratio (m/z)

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

Determining relative molecular mass from mass spectrometers

A

look at pages 13-14 of textbook 1

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

What are quantum shells?

A

Well-defined energy levels that electrons exist in

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

What are orbitals?

A

A region within an atom that can hold up to two electrons with opposite spins

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

State the location of quantum shells

A

First quantum shell is located in the region closest to the nucleus, second is in a region outside the first, the third is outside the second etc

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

What are quantum shells divided in to?

A

Subshells of slightly different energy levels

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

How many subshells are in the first quantum shell? Name

A

One - the 1s subshell

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

How many subshells in the second quantum shell? Name

A

Two - 2s and 2p. Electrons in 2p have slightly higher energy than those in 2s

20
Q

How many subshells in the third quantum shell? Name

A

Three - 3s, 3p, 3d

21
Q

How many subshells in the fourth quantum shell? Name

A

Four - 4s, 4p, 4d, 4f

22
Q

Comment on the order that electron energies increase in

A

s<p<d<f

23
Q

Describe the graphical shape of an s orbital

A

Cross axis (in + shape). Circle in the middle. Larger circle as go up (eg from 1s to 2s)

24
Q

Describe the graphical shape of a p orbital

A

Cross axis (+ shape) with an 8 shape going across the x or y axis

25
Q

How many electrons can exist in the s subshell?

A

2 (1 pair)

26
Q

How many electrons can exist in the p subshell?

A

6 (3 pairs)

27
Q

How many electrons can exist in the d subshell?

A

10 (5 pairs)

28
Q

How many electrons can exist in the f subshell?

A

14 (7 pairs)

29
Q

How many electrons can exist in each quantum shell?

A

First: 2
Second: 8
Third: 18
Fourth: 32

30
Q

What is the electronic configuration of an atom?

A

Shows the number of electrons in each sublevel in each energy level of the atom

31
Q

What is Hund’s rule?

A

States that electrons will occupy the orbitals singly before pairing takes place

32
Q

What is the Pauli Exclusion Principle?

A

States that two electrons cannot occupy the same orbital unless they have opposite spins

33
Q

How is electron spin shown?

A

Upward and downward arrows

34
Q

What is ionisation energy?

A

The energy required to completely remove an electron from an atom or element

35
Q

What is the equation for the first ionisation energy of an element (A)?

A

A(g) –> A+(g) + e-

36
Q

What is the equation for the second ionisation energy of an element (A)?

A

A+(g) –> A2+(g) + e-

37
Q

What is the trend of ionisation energies for an element (eg Na)?

A
  • First electron is considerably easier to remove than the second
  • There is a steady rise in ionisation energy for the next 8 electrons, but a big jump in energy from the 9th electron to the 10th
  • Last two electrons are much harder to remove than the previous 8
38
Q

Why are there jumps in successive ionisation energies of an element?

A
  • Last two electrons to be removed are in the first quantum shell (one that has the lowest energy)
  • The next eight electrons are in the second quantum shell, which is of lower energy than the third
  • The first electron to be removed is in the third quantum shell of highest energy
39
Q

Why do successive ionisation energies increase in magnitude?

A
  • Electron lost during ionisation is so far removed from the influence of the nucleus that it no longer experiences an attractive force from the nucleus
  • If an electron is in an orbital of a low-energy quantum shell (eg 1s orbital), then it will need more energy to be removed
40
Q

What is the equation for ionisation energy (IE)?

A

IE = energy of electron when removed - energy of electron when in the orbital

41
Q

Why is the first ionisation energy of helium larger than that of hydrogen?

A
  • 1s orbital of helium contains two electrons which increases electron-electron repulsion within the orbital (each electron shields the other from the effect of the nuclear charge). - - However, helium has a nuclear charge that is double hydrogens (as helium contains two protons opposed to hydrogens one) which decreases the energy of the 1s electrons since they are attracted more strongly.
  • The effect of the increased nuclear charge is greater than that of the increased shielding so the first ionisation energy of helium is greater than hydrogen
42
Q

Why is the first ionisation of lithium smaller than helium?

A
  • Nuclear charge of lithium is +3 (3 protons) which is larger than helium =2 (2 protons)
  • However, lithium’s outer electron is in a 2s orbital. The second quantum shell is at a higher energy than the first quantum shell
  • The electron in the 2s orbital experiences repulsion from the two inner 1s electrons (shielding from nuclear charge)
  • The latter two bullet points are more significant than increased nuclear charge so first ionisation energy of lithium is smaller than helium
43
Q

What are the three factors that affect energy an electron has?

A
  1. Orbital in which the electron exists
  2. Nuclear charge of the atom
  3. Repulsion (shielding) experienced by the electron from the other electrons
44
Q

What is the trend in ionisation energies across a period (period 2 - Li to Ne)?

A
  • As move across period 2, nuclear charge increases as number of protons increases which leads to increased attraction between nucleus and electron and therefore an increase in first ionisation energy
  • One more electron is added to the same quantum shell as go along period 2 which increases electron-electron repulsion within the quantum shell leading to a decrease in first ionisation energy
  • Increase is nuclear charge is more significant than increase in electron-electron repulsion so there is increase in first ionisation energy across period 2
  • Same can be said for period 3
45
Q

What is the trend in ionisation energies down a group (group 1 - Li to Cs)

A
  • As descend group 1, nuclear charge increases as number protons increases leading to increased attraction between nucleus and electron so therefore has an increase in first ionisation energy
  • However, one new quantum shell is added on each occasion which increases the energy of the outermost electron (because third quantum shell has higher energy value than second, and fourth quantum shell has higher energy than third; as each new quantum shell added, outer electron experiences increases repulsion (increased shielding from inner electrons)
  • Combined effect of adding an extra shell and increasing shielding is more significant than increase in nuclear charge so first ionisation energy decreases down group 1
46
Q

What other groups does the decrease in first ionisation energy down the group apply to?

A

2, 5, 6, 7 and 8

chemisry (5 decks)

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