The smallest particle of an element that retains its identity in a chemical reaction is called?
What did Democritus suggest and believe?
He suggested the existence of atoms and believed that atoms were indivisible and indestructible.
What is the scientific method?
It is a logical, systematic approach to the solution of a scientific problem.
Who used expiremental methods to transform Democritus' ideas into a scientific theory?
In Dalton's Atomic Theory, what do all atoms of a given element possess?
All atoms of a given element possess identical properties.
In Dalton's Atomic Theory, what do atoms of different elements have?
Atoms of different elements have different properties.
In chemical changes, what happens to atoms?
Atoms are neither destroyed, created, or changed.
A combination of atoms in fixed ratios of whole numbers are called?
The combination of atoms from two different elements by chemical reaction forms a?
Who discovered the electron and in what year?
J.J. Thompson (1897)
Name one change to Dalton's Theory that resulted from Thompson's work.
One change was that atoms are known to be divisible.
Name three types of subatomic particles.
Protons:positively charged subatomic particles
: Subatomic particles with no charge
Devise a way to remember that cathode is negative and an anode is postive.
There is always some postive in negative situations: C
State a finding and a conclusion by Thompson.
Thompson found that the charge-to-mass ratio is constant and concluded that electrons must be parts of all elements.
Although he did not figure out the charge or mass separately how was Thompson able to determine the charge and mass?
Since he knew the density, he could determine the mass by bending electrons in electric feilds.
What was Thompson's model called?
The "Plum Pudding" model
Who carried out experiments to find the quanity of charge carried by an electron?
What was Millikan trying to find?
He was trying to find the qantity of charged carried by an electron.
Name two subatomic particles that have the same "actual mass."
Proton and neutrons
Who conducted the Gold Foil Experiment and in what year?
Ernest Rutherford (1911)
What should have happened in Rutherford's experiment according to the accepted Plum Pudding Model?
The particles should have pass through the foil with no deflection.
Percent error = Constant reading / Tube length x 100
Test on 3/28/11