Chem 4.1 and 4.2
Positive terminal of a battery
Anode
Dalton believed all atoms of a given element are identical and atoms of a specific element are different from those or _____ _____ _______
Any other element
____________ was one of the most influential Greek philosophers
Aristotle
What two aspects of Daltons theory had to be revised as additional info was learned?
Atoms are indivisible, atoms of a given element are completely identical
Negative terminal of a battery
Cathode
Democritus thought apparent changes in matter result from changes in the groupings of atoms and not from ________ ___ _____ ______ ________
Changes in the atoms themselves
Dalton believed that in chemical reactions atoms are separated, __________, or rearranged
Combuned
Daltons atomic theory easily explains the _______ of mass in chemical reactions as being the result of separation, combination, or rearrangement of atoms
Conservation
Dalton believed atoms cannot be ______, divided into smaller particles, or ________
Created, destroyed
Democritus believed atoms could not be _______, ________, or further _________
Created, destroyed, divided
Greek philosopher _________ was the first to propose that matter was not infinitely ________ and was composed of tiny individual particles called atomos
Democritus, divisible
Democritus thought different kinds of atoms had ___________ shapes and sizes
Different
Democritus thought matter was composed of _______ _______ through which ________ move
Empty space, atoms
Daltons experimental evidence and explanation of the composition of compounds and conservation of mass led to the __________ ________ of his theory
General acceptance
What was one of Aristotle's major criticisms about atoms moving through empty space?
He did not believe that the "nothingness" of empty space could exist, he thought matter was continuous
What was shocking about Thom
It meant Dalton was wrong, there are particles smaller than atoms
J.J. Thomson, English physicist, began a series of cathode ray tube experiments in the late 1890s to determine the ratio of the cathode ray particles charge to its _________ by measuring the effect of both magnetic and electric fields on a cathode ray.
Mass
Scholarly thinkers called _______ speculated about the nature of matter and formed ________ based on their own life experiences
Philosophers, explanations
Unable to answer challenges and criticisms to his ideas, Democritus's atomic "theory" answer was eventually ___________. Without being able to conduct controlled ______________, Democritus's ideas were just that - ideas and not _______.
Rejected, experiments, science
An atom is the smallest particle of an element that
Retains the properties of that element
John Dalton, an English schoolteacher, reviewed and revised Democritus's ideas based on the results of his __________ research
Scientific
Dalton believed different atoms combine in _______ _______ ________ ________ to form compounds
Simple whole number ratios
Democritus thought the differing properties of matter are due to the ________, shape, and ___________ ___ _______
Size, movement of atoms
Democritus thought atoms were __________, homogenous, __________, and indivisible
Solid, indestructible
Why did the scientists conclude the particles were charged
The cathode ray deflected the magnetic field
What was Thompson's conclusion?
The mass of the charged particles was much less than that of a hydrogen atom
Why did scientists conclude the particles were negatively cahrged
They deflected towards the positively charged plate by an electric field
Dalton believed all matter is composed of _______ _______ __________ ______ _________
Tiny indivisible particles called atoms
The ideas of Aristotle unfortunately did gain acceptance. His influence was so great and development of science was so primitive that his denial of the existence of ________ went unchallenged for years
Unchallenged
Negative particles (first subatomic particle identified by Thompson)
electrons
Neutral particles
neutrons
Positive particles
protons