Soph Sci Ch. 4 Flashcards
the smallest particle of an element that retains the identity in a chemical reaction
Atom
Greek philosopher who said atoms were indivisible and indestructible
Democritus
Who discovered Electrons
Thompson
Electrons were discovered using a ________
Cathode Ray
In the experiment that discovered electrons the beam of light was attracted to a _________ charged plate and repelled by a ________ charged plate
positive, negative
Who discovered the charge of an electron
Millikan
Who suspended oil droplets between oppositely charged plates and studied their rate of fall
Millikan
Who discovered the nucleus and protons
Rutherford
Rutherford concluded the atom was mostly _________space with a __________ charged dense are called the _________
empty, positively, nucleus
Who shot a beam of alpha particles into gold foil expecting the alpha particles to pass through or have a slight deflect
Rutherford
Who discovered neutrons
Chadwick
Who shot a beam of alpha particles a beryllium foil, which produced a radiation that was neutrally charged and had the same mass as protons
Chadwick
the number of protons in the nucleus of an atom
Atomic Number
The number of protons ________ the number of electrons in a neutral atom
equals
the total number of protons and neutrons in an atom
Mass Number
