5.1 Flashcards
Heisenberg
Scientist that determined that it is impossible to know both the velocity and the position of a particle (electron) at the same time: uncertainty principle
Bohr
Scientist that proposed that In an atom, electrons circle the nucleus in defined paths much like the planets circle the sun.
nuclear force
The force that, if strong, results from a proper balance of protons and neutrons which allows the nucleus of an atom to maintain stability.
cation
Ion with a positive charge (metals, left side)
anion
Negative ions (elections are gained).
electron
A tiny - charged particle which fills the outer volume of an atom; responsible for the formation of chemical bonds.
neutron
A neutral particle within the nucleus which has a mass of 1 a.m.u.
proton
A particle found in the nucleus of an atom that has a charge of +1, a mass = 1 a.m.u.
Rutherford
The scientist that in 1911 used his gold foil experiment to discover the + charged nucleus of an atom; also, that atoms are mostly empty space.
Thomson
Scientist that in 1897 discovered the electron with his experiment involving cathode rays; developed the “plum-pudding” model of the atom.
John Dalton
(1803-1807) Created Modern Atomic Theory saying that all elements are made of tiny, indivisible particles called atoms; All atoms of the same element are identical, chemical reactions rearrange atoms, and that compounds are made by combining atoms in simple whole number ratios.
Democritus
(460-370 BC) Greek philosopher who developed a very basic atomic theory of matter by saying that all matter consists of tiny, indivisible particles.
decay
The process during which a nucleus undergoes spontaneous change.
mass number
The sum of the protons (+) and neutrons (0) in the nucleus of a single atom.
isotope
Atoms or elements that have the same # of protons (+) in the nucleus, but different #’s of neutrons (0).
orbit
The imaginary path of an electron around the nucleus of an atom.
atomic number
The number of protons (+) in the nucleus of an atom; unique to each different element.
atomic mass unit
A mass equivalent to 1.661 x 10⁻²⁷ Kg; each proton and neutrons = 1 a.m.u.
radioactivity
The process by which an atom spontaneously changes itself by emitting particles or energy- property of some element to break up and release energy.
ion
An atom or a small molecule with an overall + or - charge as a result of an imbalance of protons (+) and electrons (-); caused by the loss or gain of electrons (-).
nucleus
The tiny, dense core of an atom that contains all the protons and neutrons, measuring about 1/10,000 the diameter and 99.7% of the mass of an atom.
diffraction grating
A special lens through which the light of electrified elemental gases passes through to create a unique spectrum of light.
