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:

• Rutherford's nuclear model

• Plum pudding model

• Dalton’s atomic model

• Bohr’s 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.

• Dalton’s model

• Electrons orbit in fixed paths.

• Bohr’s model

• Dense nucleus surrounded by orbiting electrons.

• Plum pudding model

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

• Nuclear model

• Atoms are indivisible.

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.