History of an Atom
Believed that matter was made up by 4 properties; Hot, Cold, Dry, Wet
Questioned Democritus’s Ideas
Believed that matter was infinitely divisible
Ideas are summarized as a grave stone
Caused the death of atomic theory for 2,000 years
First to propose that matter was not infinitely divisible
Matter was composed of individual particles known as Atomos
Atomos - Uncuttable, indivisible which refers to the smallest piece of matter
Believed that atoms cannot be created, destroyed or further divided
Views are modeled as Legos because they make the foundation of atomic theory
Each of these atoms was like a Lego block: eternal, immutable, and indivisible
Atoms come in a variety of different shapes and sizes (makes the diversity if the natural world possible)
Reconciled the previous 2 ideas with his theory of atoms
he held that everything in the world was made of tiny invisible blocks which join and separate to make different things
Dominated the field of “Chemistry” for 2000 years
Believed they could turn cheap metals into gold
Used Observations and Experimentation
Discovered several elements
Irish Chemist, Physicist, inventor, and scientist
Dealt with the behavior of gases
Believed in the idea of chemical elements
Greek system of four elements finally died
First chemist to preform truly quantitative experiments
Law of conservation of mass
Found that nitrogen gas and oxygen can be chemically separated from certain compounds
Confirmed law of definite proportions
Father of modern chemistry
Lost his head in the French Revolution
Showed that the proportion by mass of the same elements in a compound is always the same (Now called the Law of Definite Proportions)
Part of our definition of a chemical - any substance with a definite composition
Best known for is Atomic Theory
Published the first table of atomic masses
Dalton’s model of a atom was the “billiard ball”
Made the Law of Multiple Proportions - When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers
All matter is composed of very small particles called atoms
Atoms of a given element are identical (Not true - isotopes)
Atoms cannot be created, destroyed or subdivided (not true - sub particles ie: e- , p+ , n*) (* = neutral)
Chemical compounds are formed when atoms of different elements combine with each other
Chemical reactions involve reorganization of the atoms - changes the way they are bound together (atoms themselves are not changed in a chemical reaction)
Used a Cathode Ray to prove the existence of negatively charged particles (AKA electrons)
Thomson’s model of an atom is called “plum pudding”
Won the 1906 Nobel Prize
Came up with the charge to mass ratio of the particles (electrons) - (-1.76×10^8 C/g)
Used oil drops to determine the magnitude of the charge on a single electron
Calculated the mass of an electron to be 9.11x10^-31 Kg
Found the charge of the electron to be -1.6×10^-19
Won Nobel Prize in 1923
Used the Gold Foil Experiment in 1911
Highly concentrated center of positive charge (Nucleus)
The atom is mostly empty space
Rutherford’s Model of an atom was called “Cherry with a pit”
Discovered the proton
Discovered the neutron
Said that the electrons are on different levels
Like the planets
Todays model of the atom called the Quantum Mechanical Model
Believed that matter was made up by 4 properties; Hot, Cold, Dry, Wet
Questioned Democritus’s Ideas
Believed that matter was infinitely divisible
Ideas are summarized as a grave stone
Caused the death of atomic theory for 2,000 years
First to propose that matter was not infinitely divisible
Matter was composed of individual particles known as Atomos
Atomos - Uncuttable, indivisible which refers to the smallest piece of matter
Believed that atoms cannot be created, destroyed or further divided
Views are modeled as Legos because they make the foundation of atomic theory
Each of these atoms was like a Lego block: eternal, immutable, and indivisible
Atoms come in a variety of different shapes and sizes (makes the diversity if the natural world possible)
Reconciled the previous 2 ideas with his theory of atoms
he held that everything in the world was made of tiny invisible blocks which join and separate to make different things
Dominated the field of “Chemistry” for 2000 years
Believed they could turn cheap metals into gold
Used Observations and Experimentation
Discovered several elements
Irish Chemist, Physicist, inventor, and scientist
Dealt with the behavior of gases
Believed in the idea of chemical elements
Greek system of four elements finally died
First chemist to preform truly quantitative experiments
Law of conservation of mass
Found that nitrogen gas and oxygen can be chemically separated from certain compounds
Confirmed law of definite proportions
Father of modern chemistry
Lost his head in the French Revolution
Showed that the proportion by mass of the same elements in a compound is always the same (Now called the Law of Definite Proportions)
Part of our definition of a chemical - any substance with a definite composition
Best known for is Atomic Theory
Published the first table of atomic masses
Dalton’s model of a atom was the “billiard ball”
Made the Law of Multiple Proportions - When two elements react to form more than one compound, a fixed mass of one element will react with masses of the other element in a ratio of small, whole numbers
All matter is composed of very small particles called atoms
Atoms of a given element are identical (Not true - isotopes)
Atoms cannot be created, destroyed or subdivided (not true - sub particles ie: e- , p+ , n*) (* = neutral)
Chemical compounds are formed when atoms of different elements combine with each other
Chemical reactions involve reorganization of the atoms - changes the way they are bound together (atoms themselves are not changed in a chemical reaction)
Used a Cathode Ray to prove the existence of negatively charged particles (AKA electrons)
Thomson’s model of an atom is called “plum pudding”
Won the 1906 Nobel Prize
Came up with the charge to mass ratio of the particles (electrons) - (-1.76×10^8 C/g)
Used oil drops to determine the magnitude of the charge on a single electron
Calculated the mass of an electron to be 9.11x10^-31 Kg
Found the charge of the electron to be -1.6×10^-19
Won Nobel Prize in 1923
Used the Gold Foil Experiment in 1911
Highly concentrated center of positive charge (Nucleus)
The atom is mostly empty space
Rutherford’s Model of an atom was called “Cherry with a pit”
Discovered the proton
Discovered the neutron
Said that the electrons are on different levels
Like the planets
Todays model of the atom called the Quantum Mechanical Model
