Question

lab worksheet: significant atomic models in history
name: signature
date: date
period: period
in this worksheet, you will explore the major historical models of the atom. for each scientist, sketch the model, write a short description, and explain its strengths (aka why its new and improved).

1. daltons solid sphere model (1803)

sketch:
description:
strengths:

1. thomsons plum pudding model (1897)

sketch:
description:
strengths:

1. rutherfords nuclear model (1911)

sketch:
description:
strengths:

Explanation:

1. Dalton's Solid Sphere Model (1803):

• Sketch: Draw a simple solid - colored sphere to represent the atom as a solid, indivisible particle.
• Description: Dalton proposed that atoms are tiny, indivisible, indestructible particles. All atoms of a given element are identical in mass and properties, and atoms combine in simple whole - number ratios to form compounds.
• Strengths: It was the first modern atomic theory. It explained the laws of conservation of mass, definite proportions, and multiple proportions in chemical reactions.

1. Thomson's Plum Pudding Model (1897):

• Sketch: Draw a sphere (representing the positive charge) with small dots (representing electrons) scattered throughout, like raisins in a plum pudding.
• Description: Thomson discovered the electron. He proposed that the atom is a uniform sphere of positive charge with electrons embedded in it to balance the positive charge.
• Strengths: It accounted for the existence of electrons within the atom and the overall electrical neutrality of the atom.

1. Rutherford's Nuclear Model (1911):

• Sketch: Draw a small, dense nucleus at the center (represented as a small circle) with electrons orbiting around it in circular paths.
• Description: Rutherford's gold - foil experiment led him to propose that the atom has a small, dense, positively - charged nucleus at its center, with electrons moving in orbits around the nucleus. Most of the atom is empty space.
• Strengths: It explained the results of the alpha - particle scattering experiment, showing that most alpha particles passed straight through the gold foil, while a few were deflected at large angles or even bounced back.

Answer:

1. Sketch: A simple solid sphere. Description: Atoms are indivisible, indestructible particles; all atoms of an element are identical; atoms combine in whole - number ratios. Strengths: Explained mass and proportion laws in reactions.
2. Sketch: Sphere with scattered dots. Description: Atom is a positive sphere with embedded electrons. Strengths: Accounted for electrons and neutrality.
3. Sketch: Small nucleus with orbiting electrons. Description: Atom has a small, dense, positive nucleus with electrons in orbits. Strengths: Explained alpha - particle scattering results.