Rutherford Gold Foil Experiment & Atomic Model Evolution

What model of the atom was proposed by J.J. Thomson?

The Plum Pudding Model, depicting the atom as a diffuse cloud of positive charge with negatively charged electrons scattered throughout.

What experiment did Ernest Rutherford conduct in 1909?

The Gold Foil Experiment, which tested the structure of the atom using alpha particles.

What was the expected outcome of Rutherford's Gold Foil Experiment based on the Plum Pudding Model?

Rutherford expected the alpha particles to pass through the gold foil with only slight deviations.

What surprising result did Rutherford observe in his Gold Foil Experiment?

A small number of alpha particles were deflected at large angles, and some bounced straight back.

What conclusion did Rutherford draw from the results of his Gold Foil Experiment?

He concluded that the atom is mostly empty space with a small, dense, positively charged nucleus at its center.

What is the nuclear model of the atom proposed by Rutherford?

A model where negatively charged electrons orbit a dense, positively charged nucleus.

What were the implications of Rutherford's Gold Foil Experiment?

It marked the birth of the nuclear model of the atom and laid the foundation for modern atomic theory.

What did Dalton's Atomic Theory state about atoms?

1. All matter is made of atoms. 2. Atoms combine in simple whole-number ratios to form compounds. 3. In reactions, atoms are combined, separated, or rearranged.

What is one aspect of Dalton's Atomic Theory that was proven wrong?

Atoms of the same element are not identical due to the existence of isotopes.

What are the three main subatomic particles and their charges?

Proton (p⁺): +1 charge, Neutron (n⁰): 0 charge, Electron (e⁻): -1 charge.

What is the atomic number (Z)?

The number of protons in an atom.

What is the mass number (A)?

The total number of protons and neutrons in an atom.

What is an isotope?

Atoms with the same atomic number (Z) but different mass numbers (A).

Who discovered the electron and how?

J.J. Thomson discovered the electron using the Cathode Ray Experiment.

What did Robert Millikan determine in his oil drop experiment?

The charge of the electron.

What did Rutherford, Geiger, and Marsden discover in their experiment?

The existence of the atomic nucleus.

What is the shape and electron capacity of an s orbital?

Spherical shape, 1 orbital, can hold 2 electrons.

What is the shape and electron capacity of a p orbital?

Dumbbell shape, 3 orbitals (x, y, z), can hold 6 electrons.

What is the shape and electron capacity of a d orbital?

Complex shape, 5 orbitals, can hold 10 electrons.

What is the shape and electron capacity of an f orbital?

Complex shape, 7 orbitals, can hold 14 electrons.

What is the formula for the speed of light?

c = λν, where c is the speed of light (3.00 × 10⁸ m/s).

What is the formula for photon energy?

E = hν or E = (hc / λ), where h is Planck's constant (6.626 × 10⁻³⁴ J·s).

How is average atomic mass calculated?

Average Atomic Mass = Σ (fractional abundance × isotopic mass).

What did J.J. Thomson conclude about the mass of the electron?

The mass of the electron is about 1/3000th of the total mass of hydrogen.

What did Thomson's experiments reveal about the atom?

They proved that there are particles smaller than an atom, specifically electrons.

What is the relationship between frequency (ν) and wavelength (λ) of a wave?

c = νλ, where c is the speed of light.

What is the significance of the Gold Foil Experiment in the history of physics?

It demonstrated the power of empirical evidence to overturn long-standing ideas and advance our understanding of atomic structure.