Atoms Flashcards
Atom
the smallest piece of matter that still remains the property of the element
Nucleus
positively charged center of the atom
protons
particles with an electrical charge of 1+
Neutrons
neutral particles that do not have an electrical charge
electrons
particles with an electrical charge of 1+
Quarks
protons and neutrons however are made up of smaller particles
Democritus
founder of the atomic theory
John Dalton
English scientist that proved atoms exist
Joseph Thompson
an English physicist, Thompson model, 1904
Ernest Rutherford
a British physicist, Rutherford model, 1911
Niels Bohr
Danish physicist, both model, 1913
electron cloud
area around a nucleas
Atomic number
number of protons in an atom
mass number
number of protons and neutrons in the nucleus of an atom
Isotopes
atoms of the same element but different number of neutrons
average atomic mass
weighted-average mass of the mixture of its isotopes
periodic table
an arrangement of elements
Dmitri Mendeleev
discovered that the elements had a periodic pattern in their chemical properties
Henry Moseley
the arrangement of elements based on their increasing atomic numbers
groups
the vertical columns in the periodic table
electron dot diagram
symbol of the element and dots to represent the electrons in the outer energy level
periods
the horizontal rows in the periodic table
