Atomic History

He believed in atomos. He was not largely supported by the scientific community at the time.

• John Dalton

• Democritus

• Ernest Rutherford

• JJ Thomson

He was an Englishman around 1800. He also believed in a hard sphere model of the atom. His atomic theory had 4 points, 2 of which are still true today.

• John Dalton

• JJ Thomson

• Niels Bohr

• Ernest Rutherford

He is responsible for discovering a small, negatively charged particle called an electron using a cathode ray tube. For this discovery, he was awarded a Noble Prize in Physics.

• John Dalton

• Niels Bohr

• JJ Thomson

• Ernest Rutherford

His model of the atom was known as the Plum Pudding Model. This model described negatively charged electrons floating in a positively charged pudding.

• John Dalton

• JJ Thomson

• Niels Bohr

• Ernest Rutherford

He was a physicist from New Zealand. His famous Gold Foil experiment used alpha particles to detect the nucleus of an atom.

• John Dalton

• JJ Thomson

• Niels Bohr

• Ernest Rutherford

One of the major conclusions of the Gold Foil experiment was that in the center of the atom existed a small, dense nucleus. What is the other major conclusion?

• The atom could implode at any time.

• The atom is made of mostly empty space.

• The nucleus has a negative charge.

• The nucleus has no charge.

This Danish physicists model of the atom is often called the planetary model. He described electrons orbiting the nucleus as our planets orbit the sun.

• John Dalton

• JJ Thomson

• Niels Bohr

• Ernest Rutherford

The quantum-mechanical model of the atom was the work of many talented scientists. Basically, it states the probability of finding a(n) _______________________ in an _______________________ at any given time.

• proton; orbit

• proton; orbital

• electron; orbit

• electron; orbital

James Chadwick was awarded the 1935 Nobel Prize in Physics for his discovery of the ___________.

• electron

• proton

• neutron

• top quark

The nucleus of an atom has a _________________ charge.

• positive

• negative

• neutral