(2.1) Definition, Composition, and History of Matter Unit 2: Matter (2.1) Definition, Composition, and History of Matter

Democritus and his ideas on atoms

Democritus’ Atoms

Lavoisier discovering elements

Some of Lavoisier’s experiments involving chemical reactions

Example of a chemical reaction showing how matter (mass) is conserved

(2.2) Development of the Atomic Model Unit 2: Matter (2.2) Development of the Atomic Model

Examples of types of models

History of the Atomic Model

John Dalton

Dalton’s Atoms

J. J. Thomson and his Cathode Ray Tube Experiment

J. J. Thomson’s Plum Pudding Model

Ernest Rutherford

Up close view of Rutherford’s gold atoms

James Chadwick

Chadwick’s proton-neutron model of the atomic nucleus

The three isotopes of Hydrogen: each contain a different number of neutrons

Niels Bohr

Quarks

Different combinations of three quarks produce either a proton or a neutron

Quarks have fractional positive and negative charges Quarks have fractional positive and negative charges. Below would be an example of a neutron

(2.3) Elements and the Periodic Table of Elements Unit 2: Matter (2.3) Elements and the Periodic Table of Elements

Dmitri Mendeleev and his periodic table of elements (next slide)

Visual Periodic Table

Comparing metals and nonmetals

Elemental Metals

Additional examples of metals

Examples of nonmetals

Example of a metalloid