Matter
Atomic Theory Timeline
Element & Atoms
Naming that Element/Formula
Polyatomic Ions
100

Anything that has mass and volume

Matter

100

Created the very first atomic theory

John Dalton

100

Number of protons in an atom

Atomic Number

100

H

Hydrogen

100

NO31-

Nitrate

200

The type of matter that is only made up of 1 type of atom or molecule

Pure Substance

200

He proposed that matter could NOT be divided into smaller and smaller pieces forever

Democritus

200

Number of protons and neutrons in an atom

Mass Number
200

NaCl

Sodium Chloride

200

ClO31-

Chlorate

300

The simplest form of matter

Elements/Atoms

300

Discovered Electrons

J.J. Thomson

300

Elements with the same # of protons but a different # of neutrons.

Isotope

300

CF4

Carbon Tetrafluoride 

300

NH41+

Ammonium

400

2+ Atoms bonded together in a set ratio

Compounds

400

Proposed the new atomic model which has electrons moving around the nucleus in a cloud

Modern Day Scientist

400

Bonds where two nonmetals share a # of electrons.

Covalent Bonds

400

LiOH

Lithium Hydroxide

400

CN1-

Cyanide

500

Made up of 2+ different substances and not chemically combined

Mixture

500

Proposed that electrons move around the nucleus in specific shells or energy levels

Neils Bohr

500

The amount of electrons the 1st, 2nd and 3rd Energy Levels can hold

2e, 8e, and 8e

500

KMnO4

Potassium Permanganate

500

HCO31-

Hydrogen Carbonate

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