atomic history Flashcards
what was Antonie Lavoisier
formulated law of conservation of matter-Matter can neither be produced nor destroyed
what law is Joseph Proust given credit for
Law of definite proportions-A compound will always be composed of the same proportions of mass, no matter the size of the compound sample, but samples that have the same ratio aren’t necessarily the same substance. (H2O always has 2 Hydrogens to 1 Oxygen atom) (CO is not equal to CO2)
What law did John Dalton discover
Law of multiple proportions
Matter is composed of exceedingly small particles called atoms. An atom is the smallest unit of an element that can participate in a chemical change.
An element consists of only one type of atom, which has a mass that is characteristic of the element and is the same for all atoms of that element (Figure 2.2). A macroscopic sample of an element contains an incredibly large number of atoms, all of which have identical chemical properties.
Atoms of one element differ in properties from atoms of all other elements.
A compound consists of atoms of two or more elements combined in a small, whole-number ratio. In a given compound, the numbers of atoms of each of its elements are always present in the same ratio.
Atoms are neither created nor destroyed during a chemical change, but are instead rearranged to yield substances that are different from those present before the change.
§ Know what two aspects of his atomic theory no longer hold true and why
Atoms are indivisible (subatomic particles)
All atoms of an element are identical (isotopes)
What was the device that JJ Thomson used for his experiment
Cathode ray tube
§ Know what happened during the experiment and what this meant
Beam bent away from negative plate, beam carried negative charge
§ Know the subatomic particle discovered from his experiment
He discovered the electron
§ Know what atomic model came from his work and what it looks like
Plum pudding model
Ernest Rutherford
gold foil experiment
discovered nucleus
james chadwick
Discovered neutrons, beam of particles did not bend away from negative or
positive plates
