Test 1 Chem 117

Front 1

Rutherford

Back 1

discovered the atomic nucleus

Front 2

What experiments did rutherford perform to find the nucleus

Back 2

he shot alpha rays through gold foil to see if the ray went all the way through. what he discovered was that 99.9% of them all went through but the rest bounced back.

Front 3

What did the discovery of neutrons conclude?

Back 3

It is how elements can have different isotopes.

Front 4

What do electrons determine?

Back 4

It determines the chemical properties of an element.

Front 5

Atomic Number?

Back 5

number of protons in nucleus: determines number of electrons so determines
the chemical identity of the atom

Front 6

Mass number?

Back 6

sum of protons and neutrons in the nucleus. Atoms with the same atomic
number but different mass numbers are isotopes of the same element

Front 7

Avogadros number

Back 7

"mole"
finds a usable weight of an element.

Front 8

λ

Back 8

wavelength

Front 9

John Dalton

Back 9

atomic theory
1808
used balance to weigh chemical reactions and their properties

Front 10

What are the two parts to Dalton's atomic theory?

Back 10

1. Atoms all have characterisic masses.
2. Atoms combine in fixed ratios

Front 11

Lavoisier

Back 11

fisrt to weigh chemical reaction
discredited the conservation of matter
balance was enabling technology

Front 12

Proust

Back 12

law of constant proportions
did similar experiment to lavoisier

Front 13

William prout

Back 13

1816
came up with half weights and isotopes

Front 14

Volta

Back 14

built the world's first battery
first supply of electrical current

Front 15

How is Volta's battery constructed

Back 15

by layering Zn and Cu interchangeably. The metals don't touch.

Front 16

Discovery of X-Rays

Back 16

Wilhem Rontgen
1895
noticed zinc sulfide glowed in a cathode ray tube and placed a piece of cardboard between a tube and the mineral still glowed.

Front 17

Discovery of Radioactivity

Back 17

1896
Bequerel
exposed minerals to sun, wrapped them in photographic film, developed them later. the film was exposed even though it was not in the sun.

Front 18

What conclusion did henri bequerel come to?

Back 18

That uranium minerals are radioactive

Front 19

Marie Curie

Back 19

A woman radiochemist that suspected other radioactive elements in uranium ore.
Extracted polonium and radium.

Front 20

3 types of radiation

Back 20

alpha rays
beta rays
gamma rays

Front 21

alpha rays

Back 21

very weak, fast He nuclei

Front 22

beta rays

Back 22

more penetrating fast electrons

Front 23

gamma rays

Back 23

very penetrating, very high energy. used in x-rays

Front 24

ν

Back 24

frequency

Front 25

c

Back 25

speed of light
should be a given constant

Front 26

diffraction

Back 26

classical experiment that shows the wave nature of light.
produce a series of light and dark fringes on a screen.

Front 27

J.J Thompson

Back 27

discovered electron
1897

Front 28

J.J. Thompson's Cathode Ray Tube

Back 28

used in t.v. to produce screen.
helped discovered the electron by measuring the charge/mass ratio

Front 29

Millikan

Back 29

1908-09
Performed oil-drop experiment

Front 30

Oil drop experiment

Back 30

determined the mass of electrons by measuring their charge.

Front 31

Plum pudding model

Back 31

a mass of positive and negatively charge particles.

Front 32

ultraviolent catastrophe

Back 32

classical wave theory predicts that the light emitted
from a heated body would contain increasing amounts of energy as the wavelength
gets shorter
could not determine why this happens

Front 33

Conservation of matter

Back 33

that the mass of reaction products is the sum of masses of the reagents, if
the experiment is done with sufficient care that all the reactants are accounted for.

Front 34

Davy

Back 34

Electrolysis
discovered alkaline metals

Front 35

E = mc2

Back 35

einestein's equation for the mass of energy
c=velocity of light

Front 36

isotopes

Back 36

atoms with identical properties but different masses

Front 37

law of multiple porportions

Back 37

when elements combine to form more than one compound, the ratio of combining masses fo one of the elements would always be in the ratio of small whole numbers

Front 38

michael faraday

Back 38

discovered electrical power current

Front 39

Packing Fracture Curve

Back 39

measurements of the tiny mass
differences (per atomic particle or nucleon) for the easy elements to analyze

Front 40

Proust

Back 40

demonstrated that for a given reaction the ratio of the reactant weights was a
constant

Front 41

vacuum pumps

Back 41

1880
led to the discovery that an electric current
could also be passed through a gas if a sufficiently high voltage was applied with the gas at a low
enough pressure

Front 42

What are some examples of exothermic energy?

Back 42

From the sun
Hydrogen bombs
Hopefully in the future hydrogen fusion reactors

Front 43

What did Aston's packing fracture curve make scientists realize?

Back 43

the enormity of the nuclear energy that could be released if, for example,
the heaviest nuclei could be broken up into smaller, lighter nuclei

Front 44

What is produced when elements are fused together?

Back 44

Energy

Front 45

Why can nuclear fusion happen?

Back 45

Because heavier nuclei are stable than the lighter ones and allow elements to fuse together to create heavier ones

Front 46

Quantum Theory

Back 46

energy is discret packets
challenges ultraviolent catastrophe
explains the power curve

Front 47

Who first developed the quantum theory?

Back 47

Max Planck 1900

Front 48

Photoelectric effect

Back 48

energy increases as wavelengths get shorter
the
maximum energy of the
electrons increases as the
wavelength of the light gets
shorter.

Front 49

Key details of the photoelectric effect

Back 49

1. electron current is proportional to the light intensity-but only if the wavelenght of light is shorter than some threshold
2. electron energy is proportional to 1/wavelength

Front 50

Albert Einstein's explanation of photoelectric effect (1905)

Back 50

light acts as a series of
particles (now called photons) with energies proportional to the frequency

Front 51

photons

Back 51

wave packets

Front 52

Bohr

Back 52

1913
applied quantum ideas to rutherford's nucleus
non radiating orbits
electrons orbit around nucleus

Front 53

What did niels bohr suggest about the stable orbits around the nucleus of an atom?

Back 53

had quantized angular
momentum

Front 54

What happend when light is absorbed by atoms?

Back 54

The electrons get excited and jump to a higher "n" value or higher shell away from the nucleus.

Front 55

What happens when light is emitted by atoms?

Back 55

The electrons jump to a lower shell closer to the nucleus.

Front 56

De Broglie

Back 56

standing waves
particles such as electrons might
have wave-like properties
uantized energy levels in atoms might have
some association with standing waves
suggested that particles should have a wavelength

Front 57

Bohr

Back 57

1913
applied quantum ideas to rutherford's nucleus
non radiating orbits
electrons orbit around nucleus

Front 58

v

Back 58

velocity

Front 59

What did niels bohr suggest about the stable orbits around the nucleus of an atom?

Back 59

had quantized angular
momentum

Front 60

Heinsberg's uncertainty principle for energy/time

Back 60

Electrons only exist in excited states for a
short time
covers a broad range

Front 61

Heinsberg's uncertainty principle for position/momentum

Back 61

If we squeeze an electron into a smaller region of
space (make Δx smaller) its momentum uncertainty Δp increases
total energy cannot be less than
the energy uncertainty

Front 62

waves

Back 62

characterized by their velocity, frequency, and length

Front 63

When do standing waves form?

Back 63

when a traveling wave is reflected so that the returning wave is exactly in phase with the arriving wave

Front 64

Schrodinger

Back 64

produced a wave equation which described an electron moving in 3
dimensions under the influence of the electrostatic attraction of the atomic nucleus