Atomic Theory Timeline

Front

What is the Electron Cloud Model?

Back

The Electron Cloud Model describes the atom as having a nucleus surrounded by a cloud of electrons that are in constant motion, rather than in fixed orbits.

Front

What material did Rutherford's team use in their gold foil experiment?

Back

Rutherford's team used gold foil to conduct their experiment, which helped to discover the nucleus of the atom.

Front

How did Rutherford's model differ from Thomson's model of the atom?

Back

Rutherford proposed that the positive charge is concentrated in the center of the atom (nucleus), while Thomson's model suggested that electrons were distributed throughout a positively charged 'plum pudding'.

Front

What is the current understanding of atomic structure?

Back

Atoms are mostly empty space, with a small nucleus at the center and electrons that swarm around it.

Front

Which of Dalton's atomic theories is no longer accepted?

Back

The idea that atoms are solid masses that can't be split into smaller particles is no longer accepted.

Front

Who proposed the first modern atomic theory?

Back

John Dalton proposed the first modern atomic theory in the early 19th century.

Front

What did Bohr contribute to atomic theory?

Back

Niels Bohr proposed that electrons orbit the nucleus in fixed paths or energy levels.

Front

What is the significance of the gold foil experiment?

Back

The gold foil experiment demonstrated that atoms have a small, dense nucleus, leading to the rejection of the plum pudding model.

Front

What is the nucleus of an atom?

Back

The nucleus is the central part of an atom, containing protons and neutrons, and is positively charged.

Front

What are protons and neutrons?

Back

Protons are positively charged particles found in the nucleus, while neutrons are neutral particles that also reside in the nucleus.