Chapter 3 Flashcards
what shape was Dalton’s Atom?
a sphere
Law of Conservation of Mass
mass cannot be created or destroyed
Who discovered the electron?
JJ Thomson
Who created the plum pudding model?
JJ Thomson
Who discovered the nucleus?
Rutherford
Where are the protons and neutrons located in an atom?
the nucleus
Where are the electrons located in an atom?
the electron cloud
How many atoms are in 1 mole?
6.022 x 10^23 atoms
What are the five parts of Dalton’s Atomic Theory?
- all matter is made up of atoms
- all atoms in one element share the same properties, atoms in a different element have different properties
- atoms cannot be created, divided, or destroyed
- atoms of different elements combine in simple whole number ratios
- in chemical reactions, atoms are rearranged
What are the exceptions to Dalton’s Atomic Theory? Why?
- all atoms in one element share the same properties, atoms in a different element have different properties (isotopes)
- atoms cannot be created, divided, or destroyed (nuclear reactions)
What did JJ Thomson use to discover the electron?
a cathode ray tube (know how this works)
What was Rutherford’s experiment called?
the gold foil experiment
Rutherford concluded that the nucleus in the center of the atom must be…
small, dense, and positive
What did Neils Bohr conclude about electrons?
electrons orbit the nucleus in specific orbits
isotopes
atoms of the same element having different masses due to varying numbers of neutrons
