Atoms Topic

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 

The central region of an atom where neutrons and protons are located is the __________________.

• nucleus 
• electron cloud
• core 
• center 

Particles in an atom that are neutral and have no charge are 

• negatrons 
• electrons 
• 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

An atom with atomic number 6 would have how many protons 

• 6
• 12
• 3
• cannot be determined