Chapter 3 Flashcards
What did Democritus call the nature basic particle?
Atoms
Atomos mean in Greek?
Invisible
What did Democritus do in 400 BC
Presented his thoughts on the particle theory
What are the signs of chemical reactions?
Color change
Precipitate is formed
Energy transfer
Gas is given off
What is the law of conservation of mass?
Matter can never be created or destroyed during chemical reactions or physical changes
What is the law of definite proportions?
A chemical compound contains the same elements in exactly the same proportions by mass regardless of the size of the sample
What is the law of multiple proportions?
H O
\/
H2O or H2O2
What is the first part of daltons theory?
All matter is composed of extremely small particles called atoms
What i the second part of daltons theory
Atoms of a given element are identical in size, mass, and other properties. Different atoms are different
What is the third part of daltons theory?
Atoms cannot be subdivided, created, or destroyed
What is the fourth part of daltons theory?
Atoms of different elements combine in simple whole number ratios to form chemical compounds
What is the fifth part of daltons theory?
In chemical reactions, atoms are combined, separated or rearranged
What 2 parts of daltons theory are wrong?
All matter is composed of atoms
Atoms of any one element differ in properties while atoms of another element remain unchanged
Who is Ernest Rutherford?
He discover the proton with the Au foil experiment
Who is J J. Thomson?
He discover the electron with the cathode ray
