Quiz 1 Flashcards
Licensed to practice law
Antoine Lavosier
Wrote “essay on Phlogiston” with help from his wife
Lavosier
Determined that Hydrogen is an element
Lavosier
discovered combustion and later developed the idea of Oxidation
Lavosier
Discovered The Law of Conservation of Mass, named after him for a while
Lavosier
Law of Conservation of Mass
Matter can neither be created nor destroyed
Beheaded for dealing with French Revolutionaries
Lavosier
Discovered Law of Definite Proportions (named after him)
Prouf
Law of Definite Proportions
a chemical compound always contains the same proportions of elements (excluding Carbon Monoxide and Dioxide)
took air samples from the atmosphere by flying in a hot air balloon
Joseph Louis Gay-Lussack
Published paper showing that a volume of oxygen gas is two times smaller than the volume of water vapor it creates (somehow water split in two pieces)
Gay-Lussack
Wouldn’t accept the idea of water molecules splitting in two
Gay-Lussack
Found out how to weigh atoms and molecules (gas) by putting them in containers and placing them on scales
Avagadro
Active in the Italian anti-monarchy revolution.
(sponsored revolutionaries) and lost his chair at the University of Turin
Avagadro
Said that putting ANY gas in a container of the same size/temperature/pressure, would have about the same number of molecules
Avagadro
Proposed that there is a difference in mass in different kinds of molecules
Avagadro
proposed that when oxygen helps form water, oxygen gas splits into two oxygen atoms
Avagadro
Invented the term “Elementary Molecules”
Avagadro
Elementary Molecules
Atoms that can no longer be broken down any further
Had a Scientific Law and Number named after him
Avagadro
Ancient Greek that developed the idea that everything is made up of invisible particles called “atoms” (not popular idea of the time)
Democritus
Two Greeks that believed that matter is continuously and infinitely divisible. (prevailing argument of the time)
Plato and Aristotle
Reintroduced Democritus’ atomic theory (1800s) to explain chemical reactions (named after him)
John Dalton
Dalton’s Atomic Theory
First person to have real data supporting the “atom” idea through observing reactions between Oxygen and Nitrogen
Dalton
Incorrectly thought that atoms and molecules were the same thing
Dalton
5 Points of Dalton’s Atomic Theory
- All matter=indivisible atoms
- An element is comprised of identical atoms
- Different elements have atoms with different masses
- Chemical compounds are made of atoms in specific integer reactions
- Atoms are neither created nor destroyed in chemical reactions.
Experimented with a Cathode Ray-discovered negatively charged particles (electrons)
J.J. Thompson
Measured electrons’ charge-to-mass-ratio and identified electrons as a fundamental particle of an atom
JJ Thompson
Studied charged oil droplets in an electric field which, when paired with Thompson’s discovery, gave electron’s mass
Robert Milikan
Believed that atoms are indivisible
Dalton
What resulted from Thompson and Milikan’s experiments
electrons have mass but it is so small that there is no measurable volume
What is the nature of an atom’s positive charge
the positive charge is in a small, massive nucleus
What were the positive particles later named
protons
Thompson’s Plum Pudding model
thought that there were randomly placed particles that surrounded the atom
Experimented by scattering alpha particles off of gold foil
Ernest Rutherford
What happened with the gold foil experiment
most particles went through but some were deflected back but a few scattered at large angles
Hypothesized that there are neutral particles in the nucleus (accounted for the difference in mass b/t elements of different atomic numbers)
James Chadwick
What are the neutral particles in the nucleus called
Neutrons
Atomic Number
the number of protons in the nucleus
How are elements distinguished from each other
by their atomic number
How many elements are currently identified on the periodic table
118
Isotopes
when a certain element has a different number of particles than stated by their atomic number
Mass Number (Atomic Weight)
the number of protons and neutrons
Atomic Mass Units (u)
1/12 of Carbon (12 Isotope Mass)
Predictions of Classical Theory (Classical Atoms) 5
- Electrons orbit the nucleus
- Curved path, change in direction=acceleration
- Accelerated charges radiate light energy
- Electrons lose energy and spiral into the nucleus
- Atoms cannot exist (but they do)
People who believed that light was a wave (3)
Huygens
Young
Maxwell
People who believed that Light was made up of particles (2)
Newton
Einstein
What is light
Light has both wave and particle nature
Did the “Two-Slit experiment” (shined a light through a hole and then 2 holes and then more holes to see how light was broken up
Young
Introduced quantized energy (discrete units called “quanta”)
Max Planck
A particle of light
Photon
Hypothesized that light is made up of quantized photons and that higher frequency photons (UV)= more energetic photons
Einstein
Blackbody Radiation (3)
- Continuous Radiation distribution
- Depends on temperature of radiating objects
- Characteristic of solids, liquids, and dense gases
Line Spectrum (3)
- Emission at characteristic frequencies
- Diffuse matter: incandescent gases
- Illustration: Balmer series of hydrogen lines
Used ROYGBIV (changing photons) to solve the Photoelectric Effect
Einstein
