Studied by 33 people
atom
the smallest particle of an element
atomic mass
a value that depends on the distribution of an elements isotopes in nature and the masses of those isotopes
atomic mass unit(amu)
one twelfth the mass of a carbon - 12 atom
dalton’s atomic theory
the first theory to relate chemical changes to events at the atomic level
electron
a negatively charged subatomic particle
cathode-ray
a stream of electrons produced at the negative electrode (cathode) of a tube containing a gas of a low pressure
group
a vertical column of elements in the periodic table; the constituent elements of a group have similar chemical & physical properties
isotopes
atoms of the same element that have the same atomic number but different atomic masses due to a different number of neurons
mass number
the total number of protons and neurons in the nucleus of an atom
neutron
a subatomic particle with no charge & a mass of one amu; found in the nucleus of an atom
nucleus
the tiny; dense central portion of an atom, composed of protons & neutrons
period
a horizontal row of elements in the periodic table
period table
an arrangement of elements in which the elements are separated into groups based on a set of repeating properties
proton
a positively charged subatomic particle found in the nucleus of an atom
