Atoms Flashcards
(22 cards)
Smallest piece of matter that still retains the property of the element
Atom
Protons and neutrons are found in a small, positively charged center of the atom
Nucleus
Particles with an electrical charge of 1+
Protons
Neutral particles that do not have an electrical charge
Neutrons
Particles with an electrical charge of 1-
Electrons
Protons and Neutrons made of smaller particles called these
Quarks
A theory that matter was uniform throughout and was not composed of smaller particles
Democritus
An English scientist who was able to prove atoms existed
John Dalton
English physicist that inferred from his experiments that atoms contained small negatively charged particles
Joseph Thomson
British Physicist that proposed that almost all the mass of an atom and all its positive charges
Ernest Rutherford
Danish Physicist that hypothesized that electrons traveled in fixed orbits around the atoms nucleus
Niels Bohr
The area around the nucleus of an atom where its electrons are most likely found
Electron Cloud
The number of protons in an atom is equal to a number
Atomic cloud
The sum of the number of protons and the number of neutrons in the nucleus of an atom
Mass number
Atoms of the same element that have different numbers of neutrons
Isotopes
The weighted average mass of the mixture of its isotopes
Average atomic mass
The elements are arranged by increasing atomic number and by changes in physical and chemical properties
Periodic table
A Russian Chemist searched for a way to organize elements
Dmitri Mendeleev
A young English scientist which led to the arrangement of elements based on their increasing atomic numbers
Henry Moseley
Or families and are numbered 1 through 18
Groups
The symbol of the element and dots to represent the electrons in the outer energy level
Electron dot diagram
