This was the first model of the atom ever proposed. It was simple and described atoms as tiny spheres that could not be broken down into smaller pieces.

• Democritus's model of the atom
• The "Plum Pudding Model" of the atom
• The "Rutherford Model" of the atom
• The "Quantum Mechanical Model" of the atom

Ernest Rutherford discovered that atoms were mostly _________________. 

• negatively charged
• positively charged
• electrons
• empty space. 

Tags

NGSS.MS-PS1-1

Discovered the electron using cathode ray tube

• Joseph Thomson
• John Dalton
• Ernest Rutherford
• Robert Millikan

Idea was of an indivisible particle of matter he called "atomos"

• John Dalton
• Aristotle
• Democritus
• Plato

What contribution did John Dalton make to atomic theory? 

• He discovered that every atom was positively charged. 
• He discovered that every element consisted of one type of atom.  
• He discovered that atoms had nuclei. 
• He discovered that atoms could be divided into smaller parts. 

J.J. Thomson provided evidence that an atom...

• is the smallest particle of matter
• contains negatively charged particles
• has an overall negative charge
• has an overall positive charge

Discovered the neutron

• Chadwick
• Rutherford
• Thomson
• Bohr

Nuclear model

• Rutherford
• Thomson
• Bohr
• Dalton

Tags

NGSS.HS-PS1-8

Discovered the electron

• Bohr
• Dalton
• Rutherford
• Thomson

Planetary model

• Thomson
• Bohr
• Dalton
• Schrodinger