Atom
Smallest part of an element that can still retain the properties of that element.
Subatomic particles
These make up the atom, and they are protons, neutrons, and electrons.
Proton
This subatomic particle is in the nucleus of the atom, and has a positive charge.
Neutron
This subatomic particle is in the nucleus of the atom, and has a neutral charge,
Electron
This subatomic particle circles the nucleus of an atom in a motion called an orbital. It has a negative charge. It also has no mass.
Quark
A particle that makes up a proton or neutron, it comes in 6 different flavors. (Sounds like ice cream!)
Atomic Number
Number of protons an element has in its atomic state.
Mass Number
The sum of the number of protons and neutrons an element has in its atomic state.
Theory
A unifying scientific explanation supported by testing.
Nucleus
The center of an atom, made of protons and neutrons.
Isotopes
Atoms with the same number of protons but different numbers of neutrons.
Model
Representation of an object or system.
Electron cloud
Region around an atom's nucleus in which electrons are likely to be found.
AMU
Stands for Atomic Mass Unit, whuch is an SI unit used to express the mass of atomic particles.
Subatomic
A word meaning "smaller than an atom
Compound
A substance formed by 2 elements.
John Dalton
An early 19th century chemis who helped to advance the belief in the existence of atoms.
Joseph Gay-Lussac
In 1809, he reported that the hydrogen reacting with oxygen to form water occupied 2� as much volume as the oxygen.
Amadeo Avogadro
Furthered the understanding of the correct chemical formulas and atomic masses.
Joseph Proust
Articulated the Law of Definite Proportions in 1799.
Ernest Rutherford
Discovered the nucleus of the arom in 1911.
Empedocles
Greek philosopher and scientist who argued that all matter was consisted of four elements: Air, Earth, Fire, and Water.
Democritus
Greek who first came up with the idea of "atomos", which means "indivisible", and he suggested that atomos were specific to the material they made up.
Aristotle
Greek philosopher who accepted the theory of Empedocles, and added his own idea that the 4 elements could be changed to one another, he set back science almost 2000 years.
Evangelista Torricelli
Italian mathematician who showed that air had weight, and invented the barometer.
David Bernoulli
Swiss mathematician who developed a theory that air and other gases consist of tiny particles that are too small to be seen.
Joseph Priestley
English scientist who experimented with mercury calx in 1773, and discovered oxygen.
Antoine Lavoisier
Frenchman who named oxygen.
Robert Boyle
Proposed a new definition of an element in around 1660.
Eugen Goldstein
Discovered, in 1886, that atoms have positive charges.
James Chadwick
Discovered the neutron of the atom in 1932.
Niels Bohr
Danish physicist that proposed that electrons do not move freely, rather they move in precise steps now known as energy levels.
Atom
Smallest part of an element that can still retain the properties of that element.
Subatomic particles
These make up the atom, and they are protons, neutrons, and electrons.
Proton
This subatomic particle is in the nucleus of the atom, and has a positive charge.
Neutron
This subatomic particle is in the nucleus of the atom, and has a neutral charge,
Electron
This subatomic particle circles the nucleus of an atom in a motion called an orbital. It has a negative charge. It also has no mass.
Quark
A particle that makes up a proton or neutron, it comes in 6 different flavors. (Sounds like ice cream!)
Atomic Number
Number of protons an element has in its atomic state.
Mass Number
The sum of the number of protons and neutrons an element has in its atomic state.
Theory
A unifying scientific explanation supported by testing.
Nucleus
The center of an atom, made of protons and neutrons.
Isotopes
Atoms with the same number of protons but different numbers of neutrons.
Model
Representation of an object or system.
Electron cloud
Region around an atom's nucleus in which electrons are likely to be found.
AMU
Stands for Atomic Mass Unit, whuch is an SI unit used to express the mass of atomic particles.
Subatomic
A word meaning "smaller than an atom
Compound
A substance formed by 2 elements.
John Dalton
An early 19th century chemis who helped to advance the belief in the existence of atoms.
Joseph Gay-Lussac
In 1809, he reported that the hydrogen reacting with oxygen to form water occupied 2� as much volume as the oxygen.
Amadeo Avogadro
Furthered the understanding of the correct chemical formulas and atomic masses.
Joseph Proust
Articulated the Law of Definite Proportions in 1799.
Ernest Rutherford
Discovered the nucleus of the arom in 1911.
Empedocles
Greek philosopher and scientist who argued that all matter was consisted of four elements: Air, Earth, Fire, and Water.
Democritus
Greek who first came up with the idea of "atomos", which means "indivisible", and he suggested that atomos were specific to the material they made up.
Aristotle
Greek philosopher who accepted the theory of Empedocles, and added his own idea that the 4 elements could be changed to one another, he set back science almost 2000 years.
Evangelista Torricelli
Italian mathematician who showed that air had weight, and invented the barometer.
David Bernoulli
Swiss mathematician who developed a theory that air and other gases consist of tiny particles that are too small to be seen.
Joseph Priestley
English scientist who experimented with mercury calx in 1773, and discovered oxygen.
Antoine Lavoisier
Frenchman who named oxygen.
Robert Boyle
Proposed a new definition of an element in around 1660.
Eugen Goldstein
Discovered, in 1886, that atoms have positive charges.
James Chadwick
Discovered the neutron of the atom in 1932.
Niels Bohr
Danish physicist that proposed that electrons do not move freely, rather they move in precise steps now known as energy levels.