Question

atomic models worksheet
use your notes and the internet to help you fill in the following outline of the history of the atom. every empty square needs to be filled in.

year	scientist	contribution	diagram
1897			image of a positively - charged sphere with negative charges embedded
1904	hantaro nagaoka		image of a circular model with a central positive part and negative charges around
		finds than an atom has a small, dense, positive nucleus and electrons are in the empty space	image of a model with a small central part and electrons outside
1913		electron moves in circular orbit at fixed distances from the nucleus
	louis de broglie	proposes that electrons have some properties of waves
	erwin schrodinger		image of an orbital model
	james chadwick

Explanation:

1897 - J.J. Thomson, discovered the electron and proposed the plum - pudding model where electrons are embedded in a positive sphere.
1904 - Hantaro Nagaoka proposed a Saturn - like model with a central nucleus and electrons in orbit.
1911 - Ernest Rutherford, through the gold - foil experiment, found an atom has a small, dense, positive nucleus and electrons in the empty space.
1913 - Niels Bohr, electron moves in circular orbit at fixed distances from the nucleus.
Louis de Broglie made his proposal in 1924.
Erwin Schrödinger developed the wave - mechanical model in 1926.
1932 - James Chadwick discovered the neutron.

Answer:

Year	Scientist	Contribution	Diagram
1904	Hantaro Nagaoka	Saturn - like model with central nucleus and electrons in orbit	A central dot (nucleus) with rings (electrons)
1911	Ernest Rutherford	Found an atom has a small, dense, positive nucleus and electrons in the empty space	Small central dot (nucleus) with electrons outside
1913	Niels Bohr	Electron moves in circular orbit at fixed distances from the nucleus	Concentric circles around a central dot (nucleus) with electrons on circles
1924	Louis de Broglie	Proposes that electrons have some properties of waves	No specific simple diagram in this context
1926	Erwin Schrödinger	Developed wave - mechanical model	Orbital shapes like the one shown in the given worksheet
1932	James Chadwick	Discovered the neutron	No specific simple diagram in this context