History of the Atom Part 1

Who discovered that the nucleus contains positively charged particles called protons?

• Ernest Rutherford
• James Chadwick
• Democritus
• Niels Bohr

Who discovered the electron?

• Niels Bohr
• Democritus
• Joseph Thomson
• John Dalton

The positive particles of an atom are 

• electrons 
• positrons 
• neutrons 
• protons 

Matter always has mass.

• true
• false

Used the word "atomos" to decsribe the uncuttable (indivisible) atom.

• Democritus

• Thomson

• Bohr

• Dalton

Proposed that electrons move around the nucleus in specific layers, or shells.

• Bohr

• Rutherford

• Chadwick

• Thomson

This picture best represents ___________________ atomic model.

• Thomson's

• Dalton's

• Bohr's

• Chadwick's

Used cathode rays to experiment with atoms.

• Rutherford

• Dalton

• Thomson

• Millikan

The scientist that discovered a positive center of an atom.

• Millikan

• Rutherford

• Dalton

• Thomson

Used alpha particles to discover the nucleus

• Thomsan

• Becquerel

• Millikan

• Rutherford