Developing a model for atoms | Exit Quiz | Oak National Academy

Which scientist is credited with the plum pudding model of the atom?

• Dalton

• Thomson

• Rutherford

• Bohr

Answer explanation

The plum pudding model, proposed by Thomson, depicted the atom as a ball of positive charge with electrons embedded within it.

Place the following atomic models in the order they were proposed, starting with the model first proposed:

• Bohr’s model

• Dalton’s atomic model

• Plum pudding model

• Rutherford's nuclear model

Answer explanation

Dalton’s model was first, followed by Thomson's plum pudding model, then Rutherford's nuclear model, and finally Bohr’s model.

What does the nuclear model of the atom suggest?

• The atom is a solid sphere.

• Electrons orbit the nucleus in fixed paths.

• The atom is mostly empty space with a dense centre.

• Negative electrons are scattered throughout a positive sphere.

Answer explanation

This model suggests a dense nucleus surrounded by electrons, with most of the atom's volume being empty space.

True or False? Chadwick’s contribution to the atomic model was the discovery of the neutron.

• True

• False

Answer explanation

Chadwick discovered the neutron, which is a neutral particle in the nucleus of an atom, contributing to the mass of atoms without a charge.

Which of the following experiments disproved the plum pudding model?

• Cathode ray tube experiment

• Gold foil experiment

• Oil drop experiment

• Photoelectric effect

Answer explanation

Rutherford’s experiment showed that alpha particles could be deflected, contradicting the plum pudding model. This experiment involved alpha particles and a thin sheet of metal.

Match the description to the correct atomic model term.

• Plum pudding model

• Atoms are indivisible.

• Nuclear model

• Electrons orbit in fixed paths.

• Dalton’s model

• Dense nucleus surrounded by orbiting electrons.

• Bohr’s model

• Atom is a ball of positive charge with embedded electrons.

Answer explanation

Bohr’s model introduced fixed electron orbits, the plum pudding model described a positive sphere with electrons, the nuclear model introduced the dense nucleus concept, and Dalton’s model viewed atoms as indivisible.