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Flashcards in Test 3- Atomic Theory Deck (75)
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1
Q

Antoine Lavoisier main

A

Law of conservation of matter

2
Q

Joseph Louis Proust main

A
  • Law of Composition
  • Law of Multiple Proportions
  • Combustion reactions
3
Q

John Dalton

A
  • Atomic Theory of Matter

- solid sphere model

4
Q

Sir William Crookes

A
  • Cathode Ray Tube
5
Q

J.J. Thompson

A

Plum pudding model

6
Q

Robert Milikan

A

Oil drop

Determined mass and charge of an electron

7
Q

Henri Bacquerel

A

Photographer

8
Q

Ernest Rutherford

A
  • Two experiments:
  • Isolated and identified alpha, beta and gamma radioactive emissions
  • gold foil experiments, and
  • Planetary model
9
Q

Aristotle

A

Thought everything was made up of 4 elements- earth, air, water, and fire. Also, student of Plato

10
Q

Democritus

A

Student of Aristotle but thought that he was wrong. Thought that everything was made up of Atoms- “indivisible” in Greek. 400 BCE

11
Q

Between these philosophers and the modern exploration of matter

A

was something called Alchemy- the making of gold

12
Q

Antoine Lavoisier

A
  • Late 1700’s
  • Father of Chemistry
  • Worked in lab and took quantitative data
  • Figured out that the mass of reactants=mass of products
  • Law of Conservation of mass (matter)- matter can not be created or destroyed in any chemical reaction.
  • E=mc^2 (Einstein) where E=energy, m=mass, and c^2=speed of light. I have no idea how this related to anything but it was in out notes ☺
13
Q

Joseph Louis Proust

A
  • 1799
  • Law of Constant proportion/Law of definite composition- The ratio of the elements in a compound remains the same. Ex. Water always has 2 hydrogen and 1 oxygen.
  • Law of Multiple Proportions- Same element can be in different compounds as long as ratio changes. Ex. H2O= 2:1 while H2O2= 1:1
14
Q

Law of Constant proportion/Law of definite composition-

A

The ratio of the elements in a compound remains the same. Ex. Water always has 2 hydrogen and 1 oxygen.

15
Q

Law of Multiple Proportions-

A

Same element can be in different compounds as long as ratio changes. Ex. H2O= 2:1 while H2O2= 1:1

16
Q

Combustion reactions

A
  • C X Hy+O2⇒CO2+H2O
  • C4H10+a lot and C8H18+a lot⇒complete combustion
  • C X Hy+O2 (limited)⇒CO+H2O (incomplete combustion)
  • C X Hy+O2 (less O2 than above)⇒C+H2O (incomplete combustion)
  • ⇒Yield sign, points to direction of reaction
17
Q

John Dalton

A
  • 1803
  • Atomic Theory of Matter:
    1. Each element is composed of extremely small particles called atoms (Democritus)
    2. All atoms of the same element are identical in chemical and physical properties, but differ from those of any other element.
    3. Atoms are neither created nor destroyed. Chemical reactions consist of the combination, separation, or rearrangement of atoms (Lavoisier)
    4. A given compound always has the same relative number and kinds of atoms (Proust)
  • Soil Sphere model
18
Q

The Atomic Theory of Matter-John Dalton

A
  1. Each element is composed of extremely small particles called atoms (Democritus)
  2. All atoms of the same element are identical in chemical and physical properties, but differ from those of any other element.
  3. Atoms are neither created nor destroyed. Chemical reactions consist of the combination, separation, or rearrangement of atoms (Lavoisier)
  4. A given compound always has the same relative number and kinds of atoms (Proust)
19
Q

Sir William Crookes

A
  • 1870s
  • Cathode Ray Tube
  • Crookes noted that the green glow moved with a magnet and moved a paddle wheel
20
Q

J.J. Thompson

A
  • Identified negative component in matter and deduced that there must be a positive part because matter is neutral
  • Dalton was wrong about model of atom. Thompson proved the presence of electrons
  • Plum pudding model/sea of electrons model- number of number of P+= number of e-
21
Q

Robert Millikan

A
  • Oil Drop experiment

- Determined the mass and change of an electron

22
Q

Henri Becquerel

A
  • Photographer

- Photographed uranium- a radioactive rock and noticed exposure

23
Q

Ernest Rutherford- Radioactive emissions

A
  • Isolated and identified alpha, beta and gamma radioactive emissions
  • 3 types of radioactive emissions
  • Ex. Of Alpha decay: 238(92)U⇒4(2)α+234(90)Th
  • Example of Beta Decay: 214(82)Pb⇒214(83)Bi+0(-1)β
  • Beta decay- neutron changes into a proton (stays in nucleus) and electron (β particle) that flies away.
  • Rutherford determined alpha and Beta particles
  • Gama in energy not a particle
24
Q

Ernest Rutherford-Gold Foil

A
  • Gold foil experiment: A ray of gama particles was shot through a piece of gold foil with photo film around it. Most of the exposure was directly across showing that most of the particles went straight though. However, some of the particles deflected showing that it bounced off something (nucleus)
  • The particles were positive so since the particles deflected, this means that the nucleus is positive since the same charge repels each other.
  • Since most of the rays went straight through, this showed that it was mostly empty space.
  • Three conclusions:
    1. Atoms have a nucleus
    2. The nucleus is positive
    3. Mostly empty space
25
Q

Ernest Rutherford- Atomic model

A
  • Model number 3 proposed by Rutherford
  • Planetary model
  • Move in circles so they don’t stick to Nucleus
  • Like an amusement park ride
26
Q

Evolution of models of the atom

A
  • Three models: Solid sphere, plum pudding, and planetary.
  • The first was solid sphere. Proposed by John Dalton before experiments like the cathode ray tube were done to find out what was inside an atom.
  • The second was the plum pudding/sea of electrons model. J.J. Thompson proposed this. He set up another cathode ray but with metal plates on the top and bottom. When the rays moved toward the positive part, he deduced that there must be a positive part since matter is neutral. He therefore identified negative component in matter, proving Dalton wrong. Protons=electrons.
  • The third model is called the planetary model proposed by Ernest Rutherford. He said that electrons move in circles around the positively charged nucleus so that they don’t stick together.
27
Q

Subatomic Particle- Relative charge

A

Proton- +1
Neutron- 0
Electron- -1

28
Q

Subatomic Particle- Mass number

A

Proton- 1
Neutron- 1
Electron- 0

29
Q

Subatomic Particle- Nuclear symbol

A

Proton- 1(1)P; 1(1)H; P+
Neutron- 1(0)n or n°
Electron- 0(-1)e or e-

30
Q

Subatomic Particle- location

A

Proton- Nucleus
Neutron- Nucleus
Electron- Around the nucleus but still inside the atom

31
Q

Relative mass

A

atomic mass unit (amu) is 1/12 the mass of a carbon-12 atom

32
Q

Nuclear symbol

A

mass P+n(# of P)X

33
Q

Nucleus-

A

P+ and n°- also called nucleons

34
Q

Number of protons is called

A

the atomic number

35
Q

Element is defined by

A

Number of protons

36
Q

Mass number=

A

P+ + n°

37
Q

Electrons are equal to

A

the number of Protons

38
Q

bottom nuclear symbol

A
  • Atomic number
  • Number of protons
  • Number of electrons (unless ion)
39
Q

Top of nuclear symbol

A

Mass number

40
Q

How to find the number of neutrons

A

mass # - # of protons

41
Q

In 14(6)C there are

A
  • 6 protons
  • 6 electrons
  • 8n(14-6)
42
Q

If given something like C-12

A
  • 12 is the mass number.
  • You know there are 6 Protons because its carbon, therefore there are 6 electrons.
  • There is 6 neutrons since 12-6=6
43
Q

Isotope

A

An atom that has the same number of protons (or the same atomic number) as other atoms of the same element do but that has a different number of neutrons (and thus a different atomic mass) Ex. C-14 and C-12

44
Q

Ion

A
  • An atom that has lost or gained electrons
  • Gained electron-Anion-Negatively charged
  • Lost election-Cation-Positively charged
45
Q

86(37)Rb+2

A

The +2 tells us that its an ion. Since its positive, it has a positive charge which means that is loses electrons. P+=37, n°=49, and e-=35 (37-2)

46
Q

Nucleons

A

protons and neutrons

47
Q

Electrostatic attraction

A

Protons and electrons attract

48
Q

Electrostatic repulsion

A

e-+e- and P+P repel

49
Q

(Strong) Nuclear force

A

the interaction that binds P+n, P+P, and n+n in nucleus.

50
Q

A nucleus is stable when

A

nuclear force and electrostatic repulsion balance out. This occurs when the ratio of n to P is between 1:1 and 1.5:1. This is also called the band of stability

51
Q

No more than ___ protons before nucleus is unstable (radioactive)

A
  • 83

- so Bismuth is ok but starting with Polomium, its not.

52
Q

Nuclear Reaction

A

A change in the nucleus of an atom

53
Q

Chemical Reaction

A

Atoms are just rearranged/combined, not changed

54
Q

Transmutational Reaction

A

Change in identity of a nucleus as a result of the number of protons changing.

55
Q

Alpha particle emissons

A
  • Rutherford-radioactive particles- Alpha particles:
  • 4(2)α- 2P and 2n from nucleus
  • Ex. 238(92)U⇒4(2)α (leaves nucleus)+ 234(90) Th. This is an example of Radioactive decay and Tansmutation
56
Q

Radioactive decay happens

A

spontaneously and by itself

57
Q

Beta particle emissions

A
  • Beta particles- n° changes into P+ and e-, P+ stays, e- is emitted
  • Ex. 214(82)Pb⇒214(83)Bi + 0(-1)β. Notice how the bottom number changes as one neutron is changed into a proton, changing the element since the number of protons determines the element.
58
Q

Nuclide

A

atom, but in nuclear activity

59
Q

radioactive decay

A

spontaneous disintegration of a nucleus into a slightly lighter nucleus accompanied by emission of particles, electromagnetic radiation, or both. Both α and β are examples of radioactive decay

60
Q

Gamma emissions

A

Gamma is the electromagnetic radiation that’s given off.

61
Q

Health risks-

A

Alpha-low, Beta-medium, Gama-high

62
Q

Half life

A

The time required to half of the atoms of a radioactive sample to decay.

63
Q

Formulas for half-life:

A
  1. Number of half-lives=time elapsed X 1 half-life/14.3 days
  2. Amount remaining= original amount X ½ for each half-life
64
Q

Fusion

A

Low-mass nuclei combine to form a heavier, more stable nucleus. Ex. Nuclear reactions

65
Q

Fission

A

A very heavy nucleus splits into more stable nuclei of intermediate mass. Ex. Sun, atomic bombs

66
Q

Fission and Fusion are both

A

not spontaneously forced

67
Q

E=mc^2

A
  • nuclear reaction energy formula

- Einstein

68
Q

Experiments with cathode rays (crooks tube) being deflected by a magnetic fields show that cathode rays are composed of particles that are.

A

-Magnetic (because its Crooks and he didn’t know about negative charge yet)

69
Q

Cathode rays are composed of particles that are now known as

A

-Electrons

70
Q

In 1911, Ernest Rutherford conducted his now famous gold foil experiment. During the experiment, alpha particles bombarded a thin piece of gold foil. The alpha particles bombarded a this piece of gold foil. The alpha particles were expected to pass easily through the gold foil. Every now and then, however, an alpha particle bounced back- an unexpected result. Rutherford concluded that these particles were striking:

A

-A tiny region of particle charge

71
Q

Rutherford called the region that deflected alpha particles:

A

A nucleus

72
Q

The total volume of the nucleus of an atom is:

A

-Very small compared with the rest of the atom

73
Q

Why did the mass increase in the open container?

A

-As matter burns, the oxygen in the air combines with the matter, adding to its overall mass. In the closed container, there was very little and limited oxygen to combine with the matter, so the mass did not increase, but remained the same due to the law of the conservation of matter.

74
Q

Ion

A

an atom, radical, or molecule that has gained or lost one or more electrons and has a negative or positive charge

75
Q

atom

A

the smallest unit of an element that maintains the chemical properties of that element