Atomic Structure and Energy Transitions

The video covers the historical development of atomic theory, starting with Democritus's idea of indivisible atoms. Lavoisier introduced the conservation of matter, while Proust established constant composition in compounds. Dalton's atomic theory laid the groundwork for modern chemistry, despite its inaccuracies. Thomson discovered the electron, leading to the plum pudding model. Millikan measured the electron's charge, and Rutherford identified the nucleus through the gold foil experiment. Finally, Bohr proposed the planetary model of electron orbits.

Who proposed the idea that matter is composed of small, indivisible particles called atoms?

• Lavoisier

• Democritus

• Proust

• Dalton

What does the law of conservation of matter state?

• Matter cannot be created or destroyed.

• Matter is composed of atoms.

• Matter can change form but not mass.

• Matter can be created and destroyed.

What did Proust's law of constant composition reveal about compounds?

• They are composed of different elements with the same mass.

• They can be created or destroyed.

• They have variable mass ratios.

• They have a definite formula and consistent mass ratios.

According to Dalton, what is true about atoms of the same element?

• They have different masses.

• They are divisible into smaller particles.

• They have the same mass.

• They can be created or destroyed.

What did JJ Thomson discover using the cathode ray tube?

• The neutron

• The electron

• The nucleus

• The proton

What was the significance of Millikan's oil drop experiment?

• It proposed the planetary model of the atom.

• It discovered the nucleus.

• It determined the charge and mass of an electron.

• It discovered the neutron.

What did Rutherford's gold foil experiment demonstrate about the atom?

• Atoms have a dense, positively charged nucleus.

• Atoms have no empty space.

• Atoms are composed of electrons and protons only.

• Atoms are indivisible.

According to Bohr's model, how do electrons move around the nucleus?

• In random paths

• In a zigzag pattern

• In fixed orbits like planets around the sun

• In a straight line

What happens when an electron moves from a higher energy level to a lower one?

• It becomes a proton.

• It absorbs energy.

• It remains in the excited state.

• It releases energy in the form of light.

Which color of light is produced when an electron transitions from a higher to a lower energy level and has the most energy?

• Blue

• Green

• Purple

• Red