Early Atomists
This ancient Greek philosopher was the first to propose the existence of atoms
Democritus
This Italian scientist developed the first vacuum and barometer using a mercury tube.
Evangelista Torricelli
This law states no matter is created or destroyed in a chemical reaction.
Law of Conservation of Mass
This subatomic particle discovered using a glass discharge tube after being repelled by a magnet
Electron
This unit is used for atomic mass, based on carbon-12 being exactly 12.
Atomic mass unit (amu)
This Greek philosopher disliked the notion of atomism because the existence of atoms necessarily requires the existence of vacuums
Aristotle
This demonstration involved two hemispheres that horses couldn't pull apart due to vacuum pressure.
Madgeburg Hemispheres
This law says compounds are made of consistent ratios of elements.
This experiment was used to find the mass-to-charge ratio of the electron
Oil drop experiment
This is the number of particles in one mole, approximately 6.022 x 10²³
Avogadro's Number
This philosopher, a follower of Democritus, integrated atomism with hedonistic ethics
Epicurus
The first vacuum used a tube of this material turned upside down into a bowl
Mercury
This law describes elements combining in whole number ratios when one has a fixed mass.
Law of Multiple Proportions
This model proposed atoms as a positive mass with electrons spread like fruit in a dessert.
Plum pudding model
Isotopes of an element differ by this number of subatomic particles
Neutrons
This 17th-century French thinker interpreted atomism through a Christian perspective
Pierre Gassendi
This man founded modern chemistry, devised the Law of Conservation of Mass, and ended up beheaded by the French Revolution
Antoine Lavoisier
This scientist discovered the Law of Multiple Proportions and developed modern atomic theory
John Dalton
Ernest Rutherford shot alpha particles at this material, revealing the nucleus
Gold foil
This is the weighted average of an element's naturally occurring isotopes.
Average atomic mass
This Roman poet expanded on atomism, arguing against free will, in his poetic work, On the Nature of Things
Lucretius
Although he lacked experimental evidence, this man hypothesized the Law of Conservation of Mass before Lavoisier
Benjamin Franklin
This scientist devised the Law of Definite Proportions
Joseph Proust
Rutherford's model describes the atom as mostly empty space, with a dense positive core.
Nuclear model
Convert 1.8066 x 1024 atoms of carbon to grams (approximately)
~36 grams