Historical Development of the Atom

The first person to ever talk about an atom was

• Democritus
• Rutherford
• Dalton

Who stated that all atoms of the same element are exactly alike?

• Democritus

• Dalton

• Thomson

• Bohr

What scientist is best known for his "Plum Pudding" model of the atom?

• J.J. Thomson

• Ernest Rutherford

• John Dalton

• Democritus

Rutherford's gold foil experiment provided evidence that...

• negative and positive charges are spread evenly throughout the atom.
• alpha particles have a positive charge.
• gold is not a dense as previously thought.
• there is a dense positively charged nucleus at the center of an atom.

Tags

NGSS.HS-PS1-8

True or False: The majority of an atom is made up of empty space

• True
• False

Tags

NGSS.MS-PS1-1

What can you conclude from the fact that scientists continue to update the atomic model?

• New information about atoms continues to be discovered
• Old information about atoms is completely useless
• Scientists did not have any information about atoms until a few years ago
• Scientists still have no idea what atoms look like

The smallest unit of an element that can exist alone and possess the properties of that element is the

• proton

• neutron

• electron

• atom

Particles having similar mass are

• protons and electrons

• neutrons and electrons

• protons and neutrons

• protons, neutrons, and electrons

Atoms are electrically neutral due to equal numbers of

• protons and electrons

• neutrons and electrons

• protons and neutrons

• protons, neutrons, and electrons

The nucleus of any potassium atom (K: atomic number 19) contains _____ protons.

• various numbers of

• 39

• 19

• none of these