Exploring Early Atomic Theory: Dalton to Millikan

The video explores the evolution of atomic theory, starting with early ideas from Aristotle and Democritus. It covers Dalton's atomic theory, which introduced the concept of indivisible atoms. The discovery of the electron by Thomson and the subsequent plum pudding model are discussed. Rutherford's gold foil experiment is highlighted, leading to the nuclear model of the atom. Finally, Millikan's oil drop experiment, which measured the electron's charge, is explained. The video emphasizes the evolving nature of atomic models as scientific understanding progresses.

What is the popular image of an atom?

• A large nucleus with orbiting electrons

• A solid sphere

• A cloud of particles

• A single particle

What did Aristotle believe about the divisibility of matter?

• Matter could be divided infinitely

• Matter could not be divided at all

• Matter could be divided only a few times

• Matter was already in its smallest form

Who believed that matter could only be divided until reaching the smallest particle called the atom?

• J.J. Thomson

• John Dalton

• Democritus

• Aristotle

What did John Dalton propose about atoms?

• Atoms can be divided into smaller pieces

• Atoms of the same element are identical

• Atoms can be destroyed

• Atoms are made of protons, neutrons, and electrons

How did Dalton come up with his model of the atom?

• By studying protons and neutrons

• Using a microscope

• Through macroscopic experiments

• By observing atoms directly

What did J.J. Thomson discover using a cathode ray tube?

• Protons

• Neutrons

• Nucleus

• Electrons

What was the 'plum pudding' model of the atom?

• A solid sphere

• Electrons embedded in a positively charged material

• A cloud of particles

• Electrons orbiting a nucleus

What did Rutherford's gold foil experiment demonstrate?

• Atoms are solid spheres

• Atoms are mostly empty space with a dense nucleus

• Electrons are in fixed orbits

• Atoms cannot be divided

Tags

NGSS.HS-PS1-8

What did Millikan's oil drop experiment measure?

• The size of an atom

• The mass of an electron

• The charge of an electron

• The density of a nucleus

Which scientist's work showed that atoms consist of mostly empty space?

• Robert Millikan

• Ernest Rutherford

• J.J. Thomson

• John Dalton