WorksheetsDiscovery of electrons and the nucleus
Total questions: 14
Worksheet time: 27mins
What were John Dalton three contributions to atomic history?
Created the atomic theory
Discovered that the atom is mostly empty space
Believed that atoms of a given element are identical
Hypothesized that the atom is a tiny, hard sphere
Believed that the universe was made of tiny "uncuttable" particles
What were J. J. Thomson's three contributions to the atomic theory?
Discovered the electron
Discovered the nucleus -did the gold foil experiment
Used the cathode ray tube in his discovery
Created a model of the atom with electrons moving around the nucleus in fixed orbits
Created the "plum pudding" model of the atom
The cathode ray experiments led to which particle being discovered?
Nucleus
Proton
Neutron
Electron
The alpha particles in Rutherford’s experiments were used to -
Identify chemical properties
Bombard sheets of gold
Identify the melting point
Determine the molecular mass
In 1897, J. J. Thomson showed that negative charges could be made to move from one end of a cathode ray tube to another, causing the tube to glow. Because of this, Thomson is credited with the discovery of the electron. Based on this information, which part of Dalton’s atomic theory conflicted with Thomson’s new data? (pg41 of notebook)
1
2
3
4
In a famous experiment conducted by Ernest Rutherford, a few positively charged alpha particles were scattered by a thin gold foil. Which of the following is a conclusion that resulted from this experiment?
The nucleus is negatively charged.
The atom is a dense solid and is indivisible.
The mass is conserved when atoms react chemically.
The nucleus is very small and the atom is mostly empty space.
Who is recognized for discovering the nucleus.
John Dalton
JJ Thomson
Ernest Rutherford
Neils Bohr
