History Of The Atom And Periodic Table Flashcards
Indirect evidence
Evidence gathered without seeing or touching an object
Nucleus
The center of the atom
Subatomic particle
Particles smaller than an atom
Atomic mass unit
Special unit used to measure a subatomic particle AMU
Model
Mental picture made using the familiar ideas to explain unfamiliar facts
Groups/families
Columns going up and down grouping elements by valence electrons
Atomic number
Number of protons in an atom
Atomic mass
Average of the existing isotope
Periods
Rows across indicating the number of energy levels(ring)
Isotope
An element with matching protons but differing number of neutrons
Mass number
The most common isotope that indicates the number of protons and neutrons in the nucleus
Valence electrons
Electrons on the outer shell/ring
Oxidation number
Charge on the ion
Democritus
Philosopher asking questions
Dalton
Came up with the atomic theory(all things are made from atoms)