Atomic Theory Timeline

A scientist conducts an experiment on the structure of atoms. The results of the experiment seem to disprove parts of the accepted atomic theory. After the scientist publishes the results, other scientists conducting the same and similar experiments obtain similar results. Which of the following will most likely happen?

• The accepted atomic theory will be changed.

• The atomic theory will continue to be accepted as it is.

• The results of the new experiments will be disregarded.

• The accepted atomic theory will be completely discarded.

The word atom comes from a Greek word "atomos" that means______.

• Invisible

• Indivisible

• Undivided

Greek philosopher that came up with the concept of "atomos"

• Democritus

• Dalton

• Thomson

• Schrodinger

The Billiard Ball is the nickname for ________ theory.

• Dalton

• Neils Bohr

• JJ Thomson

• Ernest Rutherford

John Dalton stated:

• elements are made of atoms

• atoms of a given element are identical

• atoms cannot be subdivided, created, nor destroyed

• all of the above

Tags

NGSS.HS-PS1-7

Why has the atomic theory changed over time?

• Theories always change over time.

• The feelings of scientists changed over time.

• Other scientists interpreted Democritus' evidence differently.

• After new, relevant evidence emerged, scientists reevaluated the theory.

Who proposed the first atomic theory based on scientific evidence?

• Democritus

• John Dalton

• J.J. Thomson

• Ernest Rutherford

Which experiment led to the discovery of the electron?

• Gold foil experiment

• Oil drop experiment

• Cathode ray tube experiment

• Photoelectric effect

What did the gold foil experiment conducted by Ernest Rutherford demonstrate?

• Atoms are indivisible

• Atoms have a dense nucleus

• Electrons orbit the nucleus in fixed paths

• Atoms are mostly solid

Tags

NGSS.HS-PS1-8

Which model of the atom was proposed by Niels Bohr?

• Plum pudding model

• Nuclear model

• Planetary model

• Quantum mechanical model