Chapter 2 Flashcards
Who coined the term “Atom”
Democritus
Who argued against the existence of Atoms
Plato
Who reasoned that the appearance of new substances through chemical change involved rearrangement of parts too small to be sen
Galileo
Who used atomic concepts to explain physical phenomena
Sir Isaac Newton
What are the 4 pieces of Daltons theory.
- All matter consists of extremely small particles called atoms
- atoms cannot be converted into atoms of another element
- atoms of an element are identical in mass and properties and are different from other atoms
- Compounds result from the chemical combination of a specific ration of atoms
What is used to detec contours of an atoms.
Tunneling Electron Microscope
Who created the Tunneling electron microscope
Binnig and Rohrer
Who discovered the Electron via a Cathode RAy Tube Experiment
JJ Thompson
JJ Thomson said the particles of a cathode ray of two properties
- They travel in straight lines
2. They are independant of the composition of the material from which they originate
Which experiment determined the charge on an electon and who did it.
Oil Drop experiment. Millikan
Which experiment determined the charge to mass ration of an electron and who did it
Cathode Ray Tube with capacitors and a magnet by JJ Thomson
How was the mass of an elctron first calculated
The charge from Milikans experiment divided by the mass to charge ration from JJ thomsons experiment gave us the mass.
Which Model gave us the idea that an atom is made of postive and negative charge particles uniformly
Plum Pudding by JJ Thomson and Kelvin
Which experiment gave us the atomic model today and who performed it
Rutherfords Gold Foil Experiment in which some particles bounced backwards as if hit by an extrememly desnse object
What is Rutherfords Theory
- Most of the mass and all of its positive charge are contained inside the nucleus.
- Most of the volume is empty.
- There are many electrons outside the nucleues as there are potons and these make the nucleus neutral
What was missing from the atomic theory that rutherford initially put together
Neutrons
Who later discoverd the neutron
Rutherfor and JamesChadwick
Which is slightly heavier neutrons or protons
neutrons
How much smaller is the mass of an electron than a proton and neutron relative to their mass of 1
.00055 or 1/1836
Which devices can be used help see atoms
- Electron microscope
- Scanning electron microscope
- atomic froce microscopes
What is the atomic Number and its symbol
Number of protons (Z)
What is the atomic number in the periodic table?
The number above the element.
JJ Thomson proposed that atoms contain negatively charged _______ based on experiments with cathode ray tubes
Electrons
JJ Thompson theorized that atoms must carry enough ______ charge to neutralize the negative charge of the _______.
Positive, electrons
What did Daltons postulate explain as far as scientific laws?
- Law Conservation of Mass
- Law of Constant Composition
- Law of mUltiple proportions